Scientists are racing to discover the depth of ocean damage sparked by the LA wildfires

LOS ANGELES (AP) — On a recent Sunday, Tracy Quinn drove down the Pacific Coast Highway to assess damage wrought upon the coastline by the Palisades Fire.

The water line was darkened by ash. Burnt remnants of washing machines and dryers and metal appliances were strewn about the shoreline. Sludge carpeted the water's edge. Waves during high tide lapped onto charred homes, pulling debris and potentially toxic ash into the ocean as they receded.

“It was just heartbreaking,” said Quinn, president and CEO of the environmental group Heal the Bay, whose team has reported ash and debris some 25 miles (40 kilometers) south of the Palisades burn area west of Los Angeles.

As crews work to remove potentially hundreds of thousands of tons of hazardous materials from the Los Angeles wildfires, researchers and officials are trying to understand how the fires on land have impacted the sea. The Palisades and Eaton fires scorched thousands of homes, businesses, cars and electronics, turning everyday items into hazardous ash made of pesticides, asbestos, plastics, lead, heavy metals and more.

Since much of it could end up in the Pacific Ocean, there are concerns and many unknowns about how the fires could affect life under the sea.

“We haven't seen a concentration of homes and buildings burned so close to the water," Quinn said.

Fire debris and potentially toxic ash could make the water unsafe for surfers and swimmers, especially after rainfall that can transport chemicals, trash and other hazards into the sea. Longer term, scientists worry if and how charred urban contaminants will affect the food supply.

The atmospheric river and mudslides that pummeled the Los Angeles region last week exacerbated some of those fears.

When the fires broke out in January, one of Mara Dias' first concerns was ocean water contamination. Strong winds were carrying smoke and ash far beyond the blazes before settling at sea, said the water quality manager for the Surfrider Foundation, an environmental nonprofit.

Scientists on board a research vessel during the fires detected ash and waste on the water as far as 100 miles (161 kilometers) offshore, said marine ecologist Julie Dinasquet with the University of California, San Diego’s Scripps Institution of Oceanography. Things like twigs and shard. They described the smell as electronics burning, she recalled, “not like a nice campfire.”

Runoff from rains also are a huge and immediate concern. Rainfall picks up contaminants and trash while flushing toward the sea through a network of drains and rivers. That runoff could contain “a lot of nutrients, nitrogen and phosphate that end up in the ash of the burn material that can get into the water,” said Dias, as well as "heavy metals, something called PAHs, which are given off when you burn different types of fuel.”

Mudslides and debris flows in the Palisades Fire burn zone also can dump more hazardous waste into the ocean. After fires, the soil in burn scars is less able to absorb rainfall and can develop a layer that repels water from the remains of seared organic material. When there is less organic material to hold the soil in place, the risks of mudslides and debris flows increase.

Los Angeles County officials, with help from other agencies, have set thousands of feet of concrete barriers, sandbags, silt socks and more to prevent debris from reaching beaches. The LA County Board of Supervisors also recently passed a motion seeking state and federal help to expand beach clean ups, prepare for storm runoff and test ocean water for potential toxins and chemicals, among other things.

Beyond the usual samples, state water officials and others are testing for total and dissolved metals such as arsenic, lead and aluminum and volatile organic compounds.

They also are sampling for microplastics, polycyclic aromatic hydrocarbons, or PAHs, that are harmful to human and aquatic life, and polychlorinated biphenyls, or PCBs, a group of man-made chemicals shown to cause cancer in animals and other serious health effects. Now banned from being manufactured, they were used in products like pigments, paints and electrical equipment.

County public health officials said chemical tests of water samples last month did not raise health concerns, so they downgraded one beach closure to an ocean water advisory. Beachgoers were still advised to stay out of the water.

Dinasquet and colleagues are working to understand how far potentially toxic ash and debris dispersed across the ocean, how deep and how fast they sunk and, over time, where it ends up.

Forest fires can deposit important nutrients like iron and nitrogen into the ocean ecosystem, boosting the growth of phytoplankton, which can create a positive, cascading effect across the ecosystem. But the potentially toxic ash from urban coastal fires could have dire consequences, Dinasquet said.

“Reports are already showing that there was a lot of lead and asbestos in the ash,” she added. "This is really bad for people so its probably also very bad for the marine organisms."

A huge concern is whether toxic contaminants from the fire will enter the food chain. Researchers plan to take tissue fragments from fish for signs of heavy metals and contaminants. But they say it will take a while to understand how a massive urban fire will affect the larger ecosystem and our food supply.

Dias noted the ocean has long taken in pollution from land, but with fires and other disasters, “everything is compounded and the situation is even more dire.”

The Associated Press receives support from the Walton Family Foundation for coverage of water and environmental policy. The AP is solely responsible for all content. For all of AP’s environmental coverage, visit apnews.com/hub/climate-and-environment.

FILE - Properties damaged by the Palisades Fire are seen from a coastline perspective Friday, Jan. 17, 2025 in Malibu, Calif. (AP Photo/Carolyn Kaster, File)

FILE - Beachfront properties are burned by the Palisades Fire, Sunday, Jan. 12, 2025 in Malibu, Calif. (AP Photo/Mark J. Terrill, File)

FILE - Tony Lai, center, rakes through the remains of his fire-ravaged beachfront property with his wife Everlyn in the aftermath of the Palisades Fire Tuesday, Jan. 28, 2025 in Malibu, Calif. (AP Photo/Jae C. Hong, File)

FILE - An aerial view shows the devastation by the Palisades Fire Thursday, Jan. 16, 2025 in Malibu, Calif. (AP Photo/Jae C. Hong, File)

FILE - An aerial view shows the devastation from the Palisades Fire on beachfront homes Wednesday, Jan. 15, 2025 in Malibu, Calif. (AP Photo/Jae C. Hong, File)

BRISTOL, Pa. (AP) — A thunderous explosion at a nursing home just outside Philadelphia collapsed part of the building, sent flames shooting out and left people injured and trapped inside, authorities said.

The explosion happened at Bristol Health & Rehab Center in Bristol Township, just as a utility crew had been on site looking for a gas leak, although the cause of the explosion was unclear several hours later, as was the extent of the casualties.

A plume of black smoke rose from the nursing home, as emergency responders, fire trucks and ambulances from across the region rushed there, joined by earthmoving equipment.

Authorities said there were injuries, but had yet to say whether there were any fatalities.

Police Lt. Sean Cosgrove said he didn’t know if anyone was missing, and that residents had been evacuated by emergency responders, bystanders and staff.

“A lot of the details at this point are still unknown,” he told reporters at the scene.

Bucks County emergency management officials said they received the report of an explosion at approximately 2:17 p.m. and said a portion of the building was reported to have collapsed. Ruth Miller, a Pennsylvania Emergency Management Agency spokesperson, said her agency had been informed that people were trapped inside.

Willie Tye, who lives about a block away, said he was sitting at home watching a basketball game on TV when he heard a “loud kaboom.”

“I thought an airplane or something came and fell on my house,” Tye said.

He got up to go look and saw “fire everywhere” and people escaping the building. The explosion looked like it happened in the kitchen area of the nursing home, he said. Tye said some of the people who live or work there didn’t make it out.

“Just got to keep praying for them,” Tye said.

The cause of the explosion was unclear.

The local gas utility, PECO, said its crews had responded to reports of a gas odor at the nursing home shortly after 2 p.m.

“While crews were on site, an explosion occurred at the facility. PECO crews shut off natural gas and electric service to the facility to ensure the safety of first responders and local residents,” the utility said in a statement.

Nils Hagen-Frederiksen, press secretary at the Pennsylvania Public Utility Commission, said investigators from the safety division were headed to the scene.

Hagen-Frederiksen said first responders and emergency management officials were describing it as a gas explosion, but that won’t be confirmed until his agency can examine the scene up close.

Musuline Watson, who said she was a certified nursing assistant the facility, told WPVI-TV/ABC 6 that, over the weekend, she and others there smelled gas, but “there was no heat in the room, so we didn’t take it to be anything.”

The 174-bed nursing home is about 20 miles (32 kilometers) northeast of Philadelphia. Its owner, Saber Healthcare Group, said it was working with local emergency authorities. The facility had been known until recently as Silver Lake Healthcare Center.

The latest state inspection report for the facility was in October and the Pennsylvania Department of Health found that it was not in compliance with several state regulations.

The inspection report said the facility failed to provide an accurate set of floor plans and to properly maintain several stairways, including storing multiple paint buckets and a bed frame under landings.

It also said the facility failed to maintain portable fire extinguishers on one of the three levels and failed to provide the required “smoke barrier partitions,” which are designed to contain smoke on two floors. It also said it didn’t properly store oxygen cylinders on two of three floors.

According to Medicare.gov, the facility underwent a standard fire safety inspection in September 2024, during which no citations were issued. But Medicare’s overall rating of the facility is listed as “much below average,” with poor ratings for health inspections in particular.

Associated Press reporter Holly Ramer in Concord, N.H., and Michael Casey in Boston contributed to this report. Levy and Scolforo reported from Harrisburg, Pennsylvania.

First responders work the scene of an explosion and fire at Bristol Health & Rehab Center, Tuesday, Dec. 23, 2025, in Bristol, Pa. (Monica Herndon/The Philadelphia Inquirer via AP)

Montgomery County search and rescue join first responders at the scene of an explosion and fire at Bristol Health & Rehab Center, Tuesday, Dec. 23, 2025, in Bristol Township, Pa. (Monica Herndon/The Philadelphia Inquirer via AP)

First responders work the scene of an explosion and fire at Bristol Health & Rehab Center, Tuesday, Dec. 23, 2025, in Bristol Township, Pa. (Monica Herndon/The Philadelphia Inquirer via AP)

CORRECTS NAME OF FACILITY - First responders gather at the scene of an explosion at Bristol Health & Rehab Center in Bristol Township, Pa., Tuesday, Dec. 23, 2025. (AP Photo/Tassanee Vejpongsa)

First responders gather at the scene of an explosion at Silver Lake Healthcare Center in Bristol Township, Pa., Tuesday, Dec. 23, 2025. (AP Photo/Tassanee Vejpongsa)

First responders are on the scene of a fire after an explosion at a nursing home in Bristol Township, Pa., on Tuesday, Dec. 23, 2025. (WPVI-TV/6ABC via AP)