Camp Fire 2018 Part I

 

The 2018 Camp Fire in Northern California's Butte County was one of the deadliest and most destructive wildfires in California history. The fire began on the morning of November 8, 2018, when part of a poorly maintained Pacific Gas and Electric Company (PG&E) transmission line in the Feather River Canyon failed during strong katabatic winds. Those winds rapidly drove the Camp Fire through the communities of Concow, Magalia, Butte Creek Canyon, and Paradise, largely destroying them. The fire burned for another two weeks, and was contained on Sunday, November 25, after burning 153,336 acres (62,050 ha). The Camp Fire caused 85 fatalities, displaced more than 50,000 people, and destroyed more than 18,000 structures, causing an estimated US$16.5 billion in damage.

PG&E filed for bankruptcy in January 2019, citing expected wildfire liabilities of $30 billion. On December 6, 2019, the utility made a settlement offer of $13.5 billion for the wildfire victims; the offer covered several devastating fires caused by the utility, including the Camp Fire. On June 16, 2020, the utility pleaded guilty to 84 counts of involuntary manslaughter.

Background

Fire hazard studies

The footprint of the Camp Fire had experienced 13 large wildfires since 1999 and 42 large wildfires since 1914. In 2008, the Humboldt Fire and the Butte Lightning Complex burned 100,000 acres (40,470 ha) on either side of Paradise, destroying hundreds of buildings in the region. In 2005, the California Department of Forestry and Fire Protection (Cal Fire) released a fire management plan for the region, which warned that the town of Paradise was at risk for an east wind-driven conflagration similar to the Oakland firestorm of 1991.

In June 2009, a Butte County civil grand jury report concluded that the roads leading from Paradise and Upper Ridge communities had "significant constraints" and "capacity limitations" on their use as evacuation routes. The report noted a combination of road conditions "which increases the fire danger and the possibility of being closed due to fire and or smoke", namely sharp curves, inadequate shoulders, and fire hazards adjacent to shoulders, such as "fire fuel and steep slopes". The report also recommended a moratorium on new home construction in fire-prone areas. In September 2009 however, the Butte County Board of Supervisors called the grand jury report "not reasonable", citing improved building codes and fire prevention requirements as arguments against a moratorium.

Despite these reports, Paradise city planners did not include study results in new plans. In 2009, the town of Paradise proposed a reduced number of travel lanes on the roadways and received state funding from the California Department of Transportation to implement a road diet along Skyway, Pearson Road, and Clark Road, three of the town's main thoroughfares and evacuation routes. Paradise planners opted in March 2015 to convert Skyway into a one-way route during emergencies, effectively doubling its capacity. Despite this change, the roads out of Paradise were only capable of evacuating around a fourth of the population within two hours.

Pre-fire prevention efforts

Residential development into wilderness areas, known as wildland–urban interface (WUI), requires increased state resources to safeguard these communities. To recuperate associated costs, California imposed a special fee on property owners in WUI zones; however, the fee was largely unpopular, with assemblyman Devon Mathis (Republican) claiming "not one cent has gone to putting more boots on the ground". The fee was suspended and repealed by the California State Legislature in July 2017.

Initially, much of the fire-fee revenue funded existing fire programs; the process of building out new prevention programs was slow, but the revenue did fund projects such as secondary evacuation routes and fuel reduction zones. In August 2018, three months before the fire, fire safe councils in the Paradise region were awarded $5 million in grants from the fire prevention programs to pay for fuel reduction and education projects.

Despite years of fuel reduction funded by special fees, numerous wildfires ravaged wildland–urban communities. Investigations found that PG&E power line failures during high winds had caused many of the fires. Utilities have the ability to disable dangerous power lines; however, the nearly 100-year-old transmission lines required intentional manual effort. PG&E shut off residential power to some customers, particularly in Paradise, in the days leading up to the fire. Following the 2017 North Bay fires, PG&E adopted a policy that precluded shutting off lines carrying more than 115 kV due to the number of customers who would be adversely affected by such a shutdown.

Infrastructure oversight inspection

The California Public Utilities Commission (CPUC) is responsible for inspecting PG&E's electrical infrastructure. The scope of the CPUC in relation to the scope of electrical infrastructure is unbalanced, however, and the CPUC has had difficulty fulfilling their oversight mandate.

A CPUC inspection of the section of the 115 kV Caribou-Palermo line at the origin of the Camp Fire had not been conducted in six years. Many of the electrical towers along the line are original to the Upper North Fork Feather River Project, which was constructed in the early 1900s. A 2009 inspection noted three-bolt connectors, used to join two conductors, were in need of replacement, which PG&E said had been done by 2016. In a 2011 audit, the CPUC found several thousand deficiencies, some of which PG&E disputed; it was not clear if the number of deficiencies on the Caribou-Palermo line were unusually high. A 2012 windstorm brought down five towers.

After the Camp Fire, the CPUC's Safety and Enforcement Table Mountain Division audited three years of the missing ten years of PG&E's records. Focusing on where the Camp Fire broke out, the audit found "the company was late in fixing 900 problems on its towers and other equipment, including two critical threats that regulators say languished more than 600 days before being repaired." In May 2018, the CPUC gave PG&E permission to replace the aging line, though the design did not include line hardening through high fire hazard areas.

Dry conditions

The winter of 2016–2017 saw above-average precipitation across much of California, ending a six-year statewide drought. One of the effects of the wet winter was the second spring in a row with an above-average grass crop. That winter was followed by that of 2017–2018, which was both hotter and drier than average, allowing for 'fine fuels' such as grass to carry over from the previous year. A third consecutive above-average grass crop developed following a warm and wet March 2018. This was followed by the cessation of rain in late April, and a hot and dry summer in Northern California.

Paradise received only 0.88 inches (2.2 cm) of rain between May 1 and mid-November, when it typically received more than seven inches (18 cm). The U.S. Drought Monitor had logged Butte County in the "Abnormally Dry" category beginning in late June.  By November 8, Butte County's lower elevations had gone more than 200 days without receiving one-half inch (1.3 cm) of rain. The energy release component (ERC), a metric for the dryness and flammability of vegetation, was above average all summer. As summer turned into fall and significant rain had not materialized by early October, ERC levels were well above average, and on the day of the start of the Camp Fire, they were setting records for the date. The National Fire Danger Rating System had four reporting stations in Butte County. On November 8, all of them reported fire danger ratings of "Very High" or "Extreme".

Katabatic winds

At the time of the fire's ignition, an upper-level atmospheric ridge (an elongated region of high pressure) was positioned off the coast of California. Its placement, allowing for northerly atmospheric flow, created an east–west pressure gradient. At the same time, a shortwave trough (a smaller-scale 'kink' of low pressure embedded in the flow) was moving over California, acting to intensify the pressure gradient. This created katabatic winds in many valleys in the western Sierra Nevada. Such winds form when the cool, high pressure airmass in the Great Basin spills through the narrow canyons that cut through the Sierra as it moves towards the warmer, low pressure airmass closer to the coast. The National Weather Service (NWS) described this as a "common synoptic pattern for strong winds and very dry conditions".

The NWS office in Sacramento issued a fire weather watch on November 5, which was upgraded to a red flag warning on November 6. The warning was effective for the night of Wednesday, November 7, through the morning of Friday, November 9, and it called for relative humidity levels in the single digits and wind gusts of up to 55 miles per hour (89 km/h).  The meteorologist-in-charge at the Sacramento NWS office called it "a significant red-flag event and one of the stronger ones of the season". PG&E informed 70,000 customers, residents of Paradise among them, that the utility company was considering shutting off their power to lessen the fire risk from downed power lines. PG&E eventually decided that conditions did not warrant it. The planned outage would not have prevented the Camp Fire's ignition, as the company did not de-energize transmission lines.

The downslope winds that formed on November 8 were particularly intense through Jarbo Gap,  an area where air squeezes through the Feather River Canyon from the northeast. These "Jarbo Gap winds" commonly developed in the autumn, and in the fifteen years prior to the Camp Fire, records showed 35 days with wind gusts higher than 100 miles per hour (160 km/h).

Gusty winds at Jarbo Gap began at about 7:00 p.m. on November 7 and increased over the next two hours. By 4:00 a.m. on November 8, a remote automated weather station east of Paradise was recording sustained 32-mile-per-hour (51 km/h) winds and 52-mile-per-hour (84 km/h) gusts. By the time of the Camp Fire's ignition, the Jarbo Gap weather station was recording 18-mile-per-hour (29 km/h) winds out of the northeast with 40-mile-per-hour (64 km/h) gusts. The relative humidity level was 23 percent.

Ignition

The Camp Fire was caused by the failure of a single metal hook attached to a PG&E transmission tower on the company's Caribou-Palermo transmission line, which carried power from hydroelectric facilities in the Sierra Nevada to the Bay Area. The tower, a little under 100 feet (30 m) tall, was built on a steep incline on a ridge above Highway 70 and the North Fork Feather River near the community of Pulga.

The tower had two arms, each with a hook hanging from a hole in a long piece of metal. The hook held up a string of electrical insulators. The transmission power lines were suspended from these insulators, away from the steel tower itself so as to prevent electricity arcing between them. One of the hooks on the tower (about three inches (7.6 cm) wide and one inch (2.5 cm) in diameter) had been worn down by rubbing against the metal plate that it hung from, to the point where only a few millimeters of metal remained.

At 6:15 a.m. PST on November 8, a PG&E control center in Vacaville recorded an outage on the company's transmission line in the Feather River Canyon.  The hook—which was about 7/8ths worn through—had snapped under the weight of the power line and insulator string that it supported, which weighed more than 142 pounds (64 kg).  No longer held up, the energized power line struck the transmission tower. This created an electric arc between the power line and the tower, which reached temperatures estimated at 5,000 to 10,000 °F (2,800 to 5,500 °C) and melted metal components of the conductor and the tower. The molten metal fell into the brush beneath the tower, setting it alight.

Progression

November 8

At about 6:20 a.m., a PG&E employee driving eastbound on Highway 70 in the Feather River Canyon spotted the fire and radioed his colleagues at Rock Creek Powerhouse; they called 911, who in turn transferred the call to the Cal Fire Emergency Communications Center (ECC) at 6:25 a.m. Additional calls to 911 followed, describing the fire as about 100 by 100 feet (30 by 30 m) in area, underneath the electrical transmission lines on the north side of the North Fork Feather River.

By 6:31 a.m., Cal Fire had notified firefighters at Fire Station 36 (located near Concow/Jarbo Gap) of the fire. By 6:35 a.m., two fire engines had left the station and were en route via Highway 70. They stopped above Poe Dam, on the opposite side of the Feather River, to survey the fire. At 6:44 a.m., the fire captain made an initial report to the Cal Fire ECC, describing the fire's inaccessibility and prospective growth.

We have eyes on the vegetation fire. It’s going to be very difficult access; Camp Creek Road is nearly inaccessible. It is on the west side of the river underneath the transmission lines. It’s got about a 35 miles per hour [56 km/h] sustained wind on it. We’ll keep working on access. I’m going to go up the highway to try and get a better idea about how to get to it. It’s a possibility we may have to come in off the top of Concow Road; Flea Mountain… This has got potential for a major incident. Request 15 additional engines, 4 additional dozers, 2 water tenders, 4 strike teams of hand crews. I’ll get back to you on a reporting location. — Capt. Matt McKenzie, initial report to Cal Fire Emergency Communications Center after arriving on scene at 6:44 a.m.

The fire was named after Camp Creek Road, near its place of origin. The road was unpaved and poorly maintained; it had taken one of McKenzie's engines an hour to travel one mile (1.6 km) along it during a previous fire. McKenzie requested that Cal Fire activate its aircraft earlier than their scheduled 8:00 a.m. flight time, and requested more personnel to try and stop the fire at Concow Road. At the same time, one fire engine was dispatched to Pulga and began door-to-door evacuations.  By 6:51 a.m., the Camp Fire had burned about ten acres (4 ha). The fire crested the ridge above the Feather River Canyon "shortly after" 7:00 a.m.,  and about ten minutes later, it had burned 200–300 acres (80–120 ha) and was spreading rapidly towards the community of Concow.

Fire impacts Concow

Incident command requested that an evacuation warning be issued for Concow at 7:22 a.m.  Buildings in the town began to burn by 7:25 a.m, and five minutes later Concow residents began calling 911 to report fire in their yards.  An evacuation order was requested for Concow at 7:37 a.m.  When the main fire front impacted Concow it was between one-half and one mile (0.8 and 1.6 km) across.  "Intense fire was widespread" throughout the town by 8:00 a.m., according to a federal report. 

Fire impacts Paradise

At 7:44 a.m., spot fires began to ignite in Paradise itself, ahead of the approaching main fire front. Simultaneously, the first Cal Fire air tanker left the ground at 7:44 a.m., quickly followed by an observation plane. The pilot quickly discovered that the winds were so strong—more than 50 miles per hour (80 km/h)—and the air so turbulent that fire retardant drops were impossible. The air tanker returned to base 45 minutes later, still fully loaded. Cal Fire made two more attempts to send air tankers, both of which were unsuccessful. While helicopters—better able to fly beneath the thick smoke—were able to drop water on evacuation routes over the course of the day, fixed-wing aircraft were grounded until the winds slowed.

By 7:48 a.m. people began calling 911 to report widespread spot fires on the eastern side of Paradise, 7.5 miles (12 km) from the Camp Fire's origin above the Poe Dam. At least 30 spot fires ignited within Paradise over the following 40 minutes.

Until roughly this point, the three on-duty 911 dispatchers in Paradise had been unaware of any evacuation orders or direct threat to Paradise from the fire. Dozens of people reported ash and smoke between 7:10 a.m. and 7:40 a.m., and all were told that the fire was north of Concow near Highway 70. At 7:50 a.m., a caller reporting "spot fires all over" was told that there were "no evacuations at this point." Nevertheless, the dispatchers began telling those callers from the far northeastern corner of Paradise to evacuate. The dispatchers learned of the Butte County Fire Department's orders to evacuate the entire town shortly after 8:00 a.m. and then began instructing all callers that they were under a mandatory evacuation, and should collect their belongings and leave. By 8:20 a.m., the Paradise 911 dispatch center had received 132 calls about the fire and, overwhelmed by the sheer quantity, began forwarding them to the dispatch center in Chico.

The main fire front reached Paradise at 8:30 a.m. between Apple View Way and Merrill Road. At this point it was approximately 0.6 miles (1 km) across, and shortly thereafter grew to two miles (2.8 km) wide as it grew to the south.

Remainder of the day

By 10:45 a.m., the fire had burned approximately 20,000 acres (8,100 ha).

At some point that day, emergency shelters were established. Wind speeds approached 50 miles per hour (22 m/s), allowing the fire to grow rapidly. Most residents of Concow and many residents of Paradise were unable to evacuate before the fire arrived. Due to the speed of the fire, firefighters for the most part never attempted to prevent the flames from entering Concow or Paradise, and instead sought to help people get out alive. According to Chief Scott McLean of Cal Fire, "Pretty much the community of Paradise is destroyed, it's that kind of devastation. The wind that was predicted came and just wiped it out."

The first hours saw a cascade of failures in the emergency alert system, rooted in its patchwork, opt-in nature, and compounded by a loss of 17 cell towers. Thousands of calls to 9-1-1 inundated two emergency dispatchers on duty. Emergency alerts suffered human error as city officials failed to include four at-risk areas of the city in evacuation orders and technical error as emergency alerts failed to reach 94 percent of residents in some areas and even in areas with the highest success still failed to reach 25 percent of those residents signed up.

At about 1:00 p.m., the wind slackened enough to allow fixed-wing air tankers to operate effectively. Nine air tankers operated for the next four-and-a-half hours: five S-2s, a DC-10, and three other large air tankers. They collectively dropped more than 69,000 US gallons (260 m3) of fire retardant on November 8 alone.

Fixed-wing air tankers ceased flying at 5:30 p.m. By 6:00 p.m., the fire had burned not quite 55,000 acres (22,000 ha).

November 9–25

The day after the fire started, PG&E employees noted the Big Bend's line equipment on the ground.

On November 10, an estimate placed the number of structures destroyed at 6,713, which surpassed the Tubbs Fire as the most destructive wildfire in California history, but that has since been updated to 18,793.

By November 15, 5,596 firefighters, 622 engines, 75 water tenders, 101 handcrews, 103 bulldozers, and 24 helicopters from all over the Western United States were deployed to fight the fire.

NASA satellite images show the Camp Fire between November 7 and November 12, 2018

In the first week, the fire burned tens of thousands of acres per day. Containment on the western half was achieved when the fire reached primary highway and roadway arteries that formed barriers. In the second week the fire expanded by several thousand acres per day along a large uncontained fire line. Each day, containment increased by five percent along the uncontained eastern half of the fire that expanded into open timber and high country.

November 9, the fire burned 70,000 acres (28,000 ha).

November 10, the fire was 100,000 acres (40,000 ha) and 20 percent contained.

November 13, the fire was 125,000 acres (51,000 ha) and 30 percent contained.

November 14 PG&E employees noted a broken C hook and a disconnected insulation anchor on a nearby tower.

November 15, the fire was 140,000 acres and 40 percent contained.

November 16, the fire was 146,000 acres and 50 percent contained.

November 17, the fire was 149,000 acres and 55 percent contained.

November 21, 85 percent containment; with rain falling, fire activity from November 21-on described as minimal.

November 22, 90 percent containment.

Heavy rainfall started on November 21, which helped contain the fire. Fire crews pulled back and let the rain put out the remaining fires while teams searched for victims.

The Camp Fire was declared 100 percent contained on Sunday, November 25, having burned for 17 days. This was five days ahead of the original projection for full containment on November 30, as firefighters had been aided by the recent rain. Over a thousand firefighters remained to search for any smoldering fires near the contained perimeter, clear roadways of debris and hazardous burned trees, and help with search and recovery efforts.

Effects

In context, the Camp Fire destroyed more structures than any wildfire in modern California history.

Aftermath on July 11, 2019

Casualties

There were a large number of fatalities in the first several hours of the fire, but they were not found quickly. Discovery of these early fatalities took place over the course of the following two weeks. In the first week, nearly ten victims per day were found. In the second week, that lowered to several victims per day. Victims were still being found in the third week and beyond.

November 10, fourteen bodies were discovered, bringing casualties to 23.

November 11, casualties increased to 29 after another six bodies discovered.

November 13, casualties increased to 48, making it the single-deadliest wildfire in California history, surpassing the 1933 Griffith Park Fire, which killed 29 people.

November 14, casualties increased from 48 to 56.

November 16, casualties increased from 63 to 71.

November 17, An additional five deaths brought the total to 76. President Donald Trump, Governor Jerry Brown, Governor-elect Gavin Newsom, and Federal Emergency Management Agency (FEMA) director Brock Long toured the Paradise area, and they held a short conference in the afternoon.

November 18, casualties raised to 77.

November 19, casualties raised to 79.

November 20, casualties raised to 81.

November 21, casualties raised to 83.

November 23, casualties raised to 87.

December 3, casualties revised to 85 after human remains in three separate bags were identified to be the same victim.

Identification of the deceased was hampered by the fragmentary condition of many bodies. Ten of 18 dentists in Paradise lost their offices and patient records in the fire. Two of the dead were identified from the serial numbers on artificial joints, 15 from dental records, five from fingerprints and 50 from DNA. Funerals and benefits were delayed by the identification difficulties. As of 2022, a few victims were still unidentified and undergoing testing and identification by the DNA Doe Project.

Traffic jams on the few evacuation routes led to cars being abandoned while people evacuated on foot, but did not contribute to any deaths. At least seven deaths occurred when the fire overtook people who were trapped in their vehicles, most on Edgewood Road, as well as one person outside a vehicle and two on ATVs. Some residents who were unable to evacuate survived by sheltering in place at the American gas station and the Nearly New antique store across the street. Others gathered in the nearby parking lot shared by a KMart and a Save Mart. The survival of some of those who sheltered in place has raised the question of whether in some scenarios last-minute mass evacuations provide the best outcomes, with some pointing to Australia's policy discouraging them, instituted following the 1983 Ash Wednesday brushfires in which many of the 75 dead were killed while trying to evacuate. However, 70 of the 84 fatalities listed in the Butte County District Attorney's Camp Fire investigation summary occurred inside or immediately outside the victim's residences, indicating that failure to evacuate contributed to many more deaths (70) than occurred while evacuating (8).

Many seniors were evacuated by passersby and neighbors, with at least one account of dozens of evacuees jumping into a reservoir to escape the flames.

The Camp Fire destroyed at least 12,000 buildings.

Butte County Sheriff's Department initially reported a partial death count for each community (total 67): 50 in Paradise, seven in Concow, nine in Magalia, and one in Chico.

Five firefighters were injured during two separate incidents in the first two days of the Camp Fire. In the first, one fire captain and two prison inmate firefighters were seriously burned on their upper bodies on November 8 when shifting winds trapped them on a dirt road surrounded by barbed wire as the fire encroached. In the second, a fire captain and a firefighter received face and neck burns on November 9 when a propane tank exploded as they were defending a house from the fire.

Damage and displacement

The fire forced the evacuation of Paradise, Magalia, Centerville, Concow, Pulga, Butte Creek Canyon, Berry Creek and Yankee Hill and threatened the communities of Butte Valley, Chico, Forest Ranch, Helltown, Inskip, Oroville, and Stirling City.

Burnt out vehicles abandoned along the evacuation route

The community of Concow and the town of Paradise were destroyed within the first six hours of the fire, losing an estimated 95 percent of their buildings. The town of Magalia also suffered substantial damage, and the community of Pulga, California suffered some. Nearly 19,000 buildings were destroyed, most of them homes, along with five public schools in Paradise, a rest home, churches, part of Feather River hospital, a Christmas tree farm, a large shopping center anchored by a Safeway, several fast food chains, such as Black Bear Diner and McDonald's, and numerous small businesses, as well. The Honey Run Covered Bridge over nearby Butte Creek, the last three-span Pratt-style truss bridge in the United States, was incinerated on November 10.

In May 2019, NPR reported that more than 1,000 families who were displaced by the fire were still looking for housing six months later. Rural northern California had been experiencing a severe housing shortage and growing homelessness crisis, compounded in part due to the fire. Prior to the fire, Chico had a housing vacancy rate of less than three percent. The loss of several thousand residences placed additional strain on Butte County's housing market. Average list prices for homes were reported to have increased by more than 10 percent.

Environmental impacts

The Bay Bridge in San Francisco, California. The photo on the right was taken the month preceding the Camp Fire on October 14, 2018, and the one on the left on November 16, 2018.

Bay Area air quality suffered, and for an unprecedented two days exceeded an air quality index of 200.

Smoke from the Camp Fire led to widespread air pollution throughout the San Francisco Bay Area[99] and Central Valley, prompting the closure of public schools in five Bay Area counties and dozens of districts in the Sacramento metropolitan area on November 16. Haze from smoke in the upper atmosphere was observed in New York City, more than 3,000 miles (4,800 km) away. John Balmes, a physician at the University of California, Berkeley who sits on the California Air Resources Board, noted that the fire "[resulted in] the worst air pollution [ever] for the Bay Area and northern California."

Recovery efforts were slowed as crews tested burned debris for environmental contaminants such as asbestos, volatile organic compounds, heavy metals, arsenic, dioxins, and other hazardous materials that may have burned or spread in the fire.

The Butte County health officer issued an advisory suggesting against the re-habitation of destroyed properties, warning of the potential for exposure to hazardous materials. In the weeks following the fire, Paradise City Council and Butte County Supervisors passed emergency ordinances to alleviate the delay in FEMA temporary housing by allowing residents to return to their land and live in temporary residences until the cleanup was completed and they could rebuild. However, with additional information it was clear there was a significant risk to public health and in early February 2019, FEMA's Federal Coordinating Officer David Samaniego forced policymakers to retract the accommodation and remove residents from the burn area. Those policymakers released an announcement, "The Town of Paradise and Butte County were informed that emergency ordinances intended to provide a process for citizens to return to their properties prior to removal of the debris may impact federal funding. The disaster assistance is predicated on the need to remedy health and safety hazards that pose an immediate risk to citizens prior to living in recreational vehicles on their properties with structures burned during the Camp Fire." Emotions were summed up by resident Ben Walker while addressing the Paradise City Council: "I'm asking you not to throw the people of this town into the cold in the middle of winter. If the option is to choose federal money to rebuild the town, or the people to rebuild the town—choose the people".

Multiple drinking water systems across the burn area were chemically contaminated, and contaminated building plumbing. Benzene levels found in some drinking water samples, from multiple systems, exceeded hazardous waste levels. Other contaminants such as methylene chloride, vinyl chloride monomer, naphthalene, and others were also found above allowable drinking water exposure limits. In particular, methylene chloride was present above safe drinking water limits when benzene was not detected indicating benzene was not a predictor of wildfire contaminated water. Sources of this contamination are thought to include smoke being sucked into depressurized buried and building water system components and the thermal degradation of plastics in the water systems themselves. Investigators found that traditional methods of calculating burn severity using satellite imagery were not appropriate for classifying localized burn severity within WUI communities. Density of structural loss was more predictive of water system contamination. Studies revealed significant hardship by households across the burn area who had standing homes lacking safe water. Household drinking water and plumbing education efforts were conducted by Purdue University, University of California Berkeley, Butte College, and Chico State University researchers in collaboration with the Camp Fire Zone Project. In 2020, the U.S. National Academies convened a workshop to address questions related to post-wildfire public health challenges.