Massive blast ruled out at California chemical leak in Orange County as officials say crisis is "not over"

Orange County firefighters were set to conduct another overnight operation on Monday to mitigate a chemical incident at GKN Aerospace in Garden Grove, where a compromised tank containing highly flammable methyl methacrylate was still at risk of a smaller explosion or leak of the toxic substance.

Officials said Monday that they had ruled out a worst-case scenario — a catastrophic explosion — after determining that a crack in the tank released a pressure buildup. Crews were seen on Sunday ripping weather insulation from the tank, which was at danger of overheating due to the failure of a cooling system designed to keep the chemical inside at a temperature of around 50 degrees. 

But firefighters said Monday that there was still a threat of the tank experiencing a smaller explosion or a rupture, causing a leak of the chemical used to produce plastics for airplanes.

During a news conference on Monday afternoon — five days after the chemical leak was first reported and led to the evacuation of nearly 50,000 Orange County residents from their homes — firefighters said they would send in another team at night to continue testing the pressure inside the tank. 

Officials said they would renew discussions about further reducing evacuation orders for the 16,000 people still affected after firefighters assessed the results from Monday's overnight operation.

Orange County officials said Monday that firefighters used a "deluge sprinkler system" to continuously douse a failing chemical tank at GKN Aerospace, helping to keep the temperature of the tank cool and preventing the potential of a fire. 

"So, you've got a deluge system with a full throttle on it, and then we have that ground monitor ... that's flowing 1,250 gallons a minute," OCFA Division Chief Craig Covey said. "We're talking millions and millions of gallons [of water]."

When asked if the water being used on the tanks was being tested for contaminants, Covey said that it was part of standard operations at any incident involving a hazardous material.

"We are absolutely testing runoff — that is normal operating procedure. Plus, the teams put downstream barriers to capture ... anything floating," Covey said. "[The water is] 100 percent clean, and it's been clean the entire time we've been monitoring it."

Covey also noted that those living in the evacuation zone would "absolutely not" have to wash down the exteriors of their homes, outdoor furniture or walkways. 

"If anything released [from the tank] in the very beginning stages of this [incident] ... it settled down in that immediate area," Covey said. "We had no winds. There was nothing that was really pushing this incident, other than the pressure being developed in the tank."

Orange County Fire Authority Hazmat Branch Division Chief Nick Freeman said that crews hoped to see the internal temperature of the tank continue trending downwards overnight. Officials said that the temperature inside the tank was approximately 100 degrees on Saturday night, but noted it had since flattened and decreased to around 93 degrees by Monday evening.

"Under normal conditions, it is around 50 [degrees] with that cooling system in place," Freeman said of the tank's internal temperature. "That cooling system is not in place, so we're just gonna watch the trending, continue talking to the chemists and the experts ... to make sure we're in the right direction moving forward."

Garden Grove Police Chief Amir El-Farra said that seven arrests have been made since the start of the toxic chemical incident at GKN Aerospace on Thursday night, when evacuation orders were first issued. 

"Unfortunately, during incidents like this, we do have bad actors," El-Farra said. 

One person was arrested for looting and six were arrested for prowling, El-Farra said, noting that the Orange County District Attorney's Office would prosecute them "to the fullest extent of the law." 

"We take high visibility patrol, plain clothes details and the latest law enforcement technology to make sure our communities are safe," El-Farra said. "We will continue to do that in these areas that are impacted."

He said that evacuees returning home Monday night could expect to see Garden Grove police officers patrolling the area in increased numbers.

Orange County officials said Monday that they were reducing the evacuation zone near the Garden Grove chemical incident by 65 percent, allowing tens of thousands of people to return home after five days of uncertainty. 

Garden Grove Police Department Chief Amir El-Farra announced that the new zone would include homes and businesses for approximately 16,000 residents in an area bounded by Orangewood Avenue to the north, Dale Street to the east, Knott Street to the west and Garden Grove Boulevard to the south.

He urged people to remain mindful of the evacuation orders as crews continued working around the clock to completely contain the incident. 

When asked whether evacuees should be worried about contamination, Orange County Health Care Agency Dr. Regina Chinsio-Kwong said that while the work isn't over yet, people returning home on Monday "can feel safe."

"There was no contamination," she said. "You should feel comfortable going home, even if you're across the street from that new zone line."

Orange County Fire Authority Division Chief and Incident Commander Craig Covey said that with new information, officials were able to discuss reducing evacuation zones, which were established on a five-day scale, while monitoring the "worst possible" weather conditions forecasted for the region.

"We built our evacuation footprint on a 360-degree assessment of that, so that if we have a wind change that [is] unexpected, we are covered as well. So, that modeling — both plume and potential fire — is covered in this evacuation zone."

He said that the smaller evacuation zone is still in place because crews "still have hazards in this incident that we're trying to tend and fix."

Covey said that additional repopulation of evacuees would be considered using the same process. 

"I'm very, very optimistic moving forward, that we're gonna continue with the success, that everything is stabilizing and we're gonna get them home as soon as possible," he said.

Democratic Senator Adam Schiff also spoke at the conference, urging people to continue heeding evacuation orders. 

"I want to urge folks that are still within the area where there is an evacuation order ... Nothing is worth risking, endangering your lives by trying to go back to your home while there is an evacuation order still in effect," he said.

Officials and first responders gathered in Orange County on Monday night to provide updates on the chemical leak at an aerospace facility in Garden Grove, describing what they said were successful efforts overnight to reduce the risk to the public and allow evacuated residents to return home.

"We knew we had to come up with a plan. That's what we do," Orange County Fire Authority Interim Chief TJ McGovern said. "Throughout the day today, I'm happy to report the most catastrophic and worst case scenario was mitigated and resolved." 

But McGovern noted said that there was still much work for emergency crews to do, including work to mitigate potential for a smaller explosion or spill of the methyl methacrylate stored inside the cracked tank. 

"It's not over yet," McGovern said. "We still have work to do." 

"I was handed an incident that had two options: a spill or an explosion," OCFA Division Chief and Incident Commander Craig Covey said. "As the chief said, it was unacceptable. … We found a plan and we [implemented] it. That took time."

Covey said that in the last 24 hours, firefighters and experts have been monitoring the temperature inside the tank, removing weather insulation to increase cooling efficiency and testing a pressure release.

"A lot of people were asking us why aren't we getting the tank [temperature] numbers more often," Covey said. "We were not putting firefighters down range into the area during the daylight when the tank is as its most vulnerable."

Covey said that officials believe most of the substance in the tank has cured and hardened.

U.S. Environmental Protection Agency On-Scene Coordinator Chris Myers said that throughout the response process, teams from the agency have been monitoring air quality in the area. 

"All the air monitoring instrumentation that we've been operating has been operating 24 hours a day, around the clock and there have been no [air quality] exceedances detected throughout the duration of the incident."

Orange County school districts on Monday announced their plans for the week ahead after more than a dozen Garden Grove Unified School District campuses were closed on Friday due to evacuation orders, with Savanna, Westminster and Cypress school districts following suit.

The plans were announced as uncertainty still surrounds the timetable for the Orange County chemical incident response, and as 50,000 evacuees remain displaced from their homes.

• Garden Grove Unified School District: Officials have announced that impacted campuses will transition to distance learning, and that instructions will be provided from the principal or teachers to students and their families. Those prevented from joining class due to evacuation conditions will not be held responsible as "the safety of our students, staff, and community remains our highest priority," district officials said.
• Magnolia School District: Robert M. Pyles STEM Academy in Stanton will remain closed in the coming days, according to the Orange County Sheriff's Department's Disaster Resources website. 
• Savanna School District: All campuses, some of which host Summer Academy, were will be closed through Friday. Summer Academy will be delayed by one week and begin on June 1.
• Westminster School District: Fryberger Elementary and Sequoia Elementary schools, both of which are inside the evacuation zone, will be closed until deemed safe by Orange County officials. Students at those campuses will receive online learning instructions beginning on Tuesday. 

In a post to X on Monday afternoon, the Orange County Fire Authority said officials were "re-evaluating" evacuation zones after the threat of a massive explosion at the GKN Aerospace facility in Garden Grove was ruled out.

"Due to the threat of the BLEVE being eliminated, Fire & Law are re-evaluating the evacuation zones," the post reads, referring to a Boiling Liquid Expanding Vapor Explosion event. "Please do NOT enter the evacuation zones at this time."

It's not yet clear if any evacuation orders will be lifted.

The OCFA has scheduled a 6 p.m. Pacific Time news conference in Los Alamitos.

United Kingdom-based GKN Aerospace paid nearly $1 million to settle a lawsuit with California regulators after the company was accused of emitting toxic or volatile compounds into the air at its Garden Grove facility.

The lawsuit brought by the South Coast Air Quality Management District, which provided a copy of the 2024 settlement agreement to CBS LA, stemmed from a variety of alleged violations by GKN, including a failure to obtain appropriate permits.

South Coast AQMD alleged that the GKN Aerospace site was the source of emissions of VOCs or volatile organic compounds. Methyl methacrylate, the substance inside the tank at the center of the chemical incident at the Garden Grove site, is a VOC. However, the settlement does not specify if methyl methacrylate was the VOC allegedly emitted at the GKN site in violation of California regulations.

GKN agreed to pay $909,935 to South Coast AQMD by January 6, 2025.

CBS LA reached out to GKN for comment on the settlement, but was directed to the company's website for a statement. The statement on the website addressed the current ongoing crisis, but not the settlement.

The Orange County Register first reported the settlement on Saturday.

Orange County District Attorney Todd Spitzer announced on Saturday that his office had launched an investigation into the company after the crisis began.

"For goodness' sake, they're in the middle of a commercial area, residential, it's an urban population. ... It's irresponsible, it's horrific, and I'm angry about it," Spitzer said in an interview. "I'm gonna channel my anger to continue to protect the public. ... Tonight, we are not getting satisfactory answers. But in the future, I can assure you we will."

California Gov. Gavin Newsom announced Monday that President Trump had approved the state's request for a federal emergency declaration in Orange County.

The approval will allow the Federal Emergency Management Agency, or FEMA, to "direct federal assistance with personnel, equipment, and other specialized resources to support life-saving response," according to Newsom's office.

"California didn't wait for this situation to escalate — we moved early, aggressively, and in close partnership with local responders to protect lives and support impacted communities," Newsom said in a statement. "We are grateful for the federal government approving our request and helping strengthen the resources already on the ground to help this community recover safely."

According to FEMA, a Presidential Emergency Declaration differs from a Presidential Major Disaster Declaration in that it provides preemptive and protective action, while the latter provides assistance after a disaster causes significant damage.

An Orange County Fire Authority spokesperson on Monday qualified an earlier update provided by officials, noting that although the threat of a massive explosion has been ruled out at GKN Aerospace in Garden Grove, the potential exists that a smaller blast could occur at the site of the chemical incident. 

While the risk of a worst-case scenario BLEVE, or Boiling Liquid Expanding Vapor Explosion, has been "eliminated," according to OCFA Interim Chief TJ McGovern, an agency spokesperson said the remaining flammable material in the tank still has the potential to burn and ignite.

On Friday, OCFA Incident Commander and Division Chief Craig Covey said officials had determined there were two possible outcomes for a tank containing methyl methacrylate that was "actively in crisis."

"There are literally two options left remaining: One, the tank fails and spills a total of about [6,000] to 7,000 gallons of very bad chemicals into the parking lot and that area," Covey said. "Or two, the tank goes into a thermal runaway and blows up, affecting the tanks that are around it that have fuel or chemicals in them as well." 

Orange County Fire Authority Interim Chief TJ McGovern said evacuation zones were "still in play" as of Monday morning following a determination by officials that the Garden Grove chemical tank was no longer at risk of exploding.

"Please abide by those evacuation zones," he said. 

The situation at the site of the chemical incident remains active, said OCFA spokesperson Nick Garton, who noted that he could not provide information as to when when evacueees would be allowed to return to their homes.

"I don't have a hard timeline but I can say this was a huge step in the right direction toward getting a resolution there," Garton said of Sunday's overnight operation to determine pressure inside the compromised tank containing methyl methacrylate, a highly flammable, toxic substance used to produce plastics.

About 50,000 residents remain evacuated with officials emphasizing that the threat of a toxic leak still remains a possibility.

Orange County Fire Authority public information officer Nick Garton said the agency was weighing options Monday morning as it decides on next steps following a determination that the compromised chemical tank was no longer at risk for explosion.

"They are still working on all sorts of different plans, depending on the variables that they're dealt with, as far as the temperature and the chemical itself," he said.

Crews are waiting until nightfall to continue work on the tank, as higher temperatures present greater risk. Internal temperatures on the tank cannot be read via drone, Garton said.

"As we continue to monitor that temperature with the sun and the ambient temperatures during the day, hopefully it continues to trend in the right direction," Garton said. "We anticipate it doing so and then we can form some more concrete timelines to get people back home, people back into their businesses."

The threat of toxic chemicals leaking out of the tank at the center of the Garden Grove hazmat incident is still possible, according to Orange County Fire Authority public information officer Nick Garton.

"It's still a potential," Garton told CBS LA on Monday after officials announced that the threat of an explosion at the site had been eliminated. "We're trying to confirm that there's still a liquid form of this chemical that could potentially leak out."

Garton made it clear that there is no active leak, but said additional cracks could potentially form at the bottom of the tank. As pressure continues to lower, however, so do the chances of cracks forming, he said.

OCFA Incident Commander Craig Covey warned the public on Friday that the spillage of "a total of about [6,000] to 7,000 gallons of very bad chemicals into the parking lot and that area" was one of two possibilities that could result from the tank failing. The other possibility, he said, was a catastrophic blast known as a BLEVE incident, or Boiling Liquid Expanding Vapor Explosion.

Orange County Fire Authority Incident Commander and Division Chief Craig Covey said "risk management" reasons prevented offials from providing more frequent updates on the tank's internal temperature over the weekend.

"The risk management to our firefighters' safety was first and foremost," he said on Monday. "We were not doing tank temperature checks during the day while the sun was on it in the most extreme conditions for that tank to go the wrong direction. We were only doing tank temperatures at night."

He said OCFA crews used the daytime hours to work on other objectives. 

"That's why there were delays in getting you guys that information, because we didn't want to put our members in harm's way," Covey said.

Orange County officials responding to a California chemical leak announced on Monday morning that the threat of a BLEVE, or Boiling Liquid Expanding Vapor Explosion, has been eliminated after an overnight operation.

"We are happy to report that the threat of a BLEVE is now off the table," Orange County Fire Authority Interim Chief TJ McGovern said. "That threat has been eliminated."

In a post on X, McGovern and OCFA Incident Commander and Division Chief Craig Covey said crews confirmed a crack on the tank, which led to a pressure release. The tank's internal temperature has decreased from 100 degrees to 93 degrees.

"That is incredibly positive news as we turn the corner on this incident," Covey said.

A White House official told CBS News on Monday that the Trump administration "is engaged and monitoring the situation in Garden Grove," noting that federal resources were assisting with the response.

"The U.S. EPA has integrated with the local Unified Command composed of state and local agencies, and has enabled air monitoring at 20 locations around the area," the White House official said. "FEMA has deployed a Liaison Officer to coordinate with officials and has also deployed a team to the State Emergency Operation Center to support incident contingency planning. FEMA has also activated the Interagency Modeling and Atmospheric Assessment Center to provide plume modeling of airborne hazards, informing incident leadership and contingency planning." 

Gov. Gavin Newsom asked President Trump on Sunday for a federal emergency declaration. U.S. Sens. Alex Padilla and Adam Schiff of California, Orange County Rep. Derek Tran, and local officials including Orange County Supervisor Janet Nguyen, wrote Mr. Trump in support of the request.

On Saturday, Newsom proclaimed a State of Emergency for the Orange County chemical incident, leading to the deployment of nearly 800 first responders and experts to assist local agencies in Garden Grove. Emergency personnel working to respond to the crisis include firefighters, law enforcement, hazmat teams, scientists, toxicologists, engineers, and public health and sheltering experts. 

Tens of thousands of Orange County residents in the communities of Garden Grove, Buena Park, Anaheim, Stanton, Westminster and Cypress have been under mandatory evacuation orders since Friday afternoon as officials worked to mitigate the chemical incident emergency at GKN Aerospace. 

Nearly 10 shelters have been opened across the region, many of which have reached or are nearing capacity and straining the resources provided by Red Cross volunteers. Local officials have worked to facilitate the opening of additional shelters as necessary, with two new sites opening on Sunday, including one at the Orange County Fairgrounds for evacuees in RVs. 

On Sunday, California State Parks officials advised those displaced from their homes that they cannot stay at state parks overnight, including at Bolsa Chica State Park in Huntington Beach. In a post to X, parks officials said that their parking lots and parks were not equipped to accommodate the needs of evacuees. 

Orange County Fire Authority Interim Chief TJ McGovern said in a post to X on Sunday evening that crews were preparing for an "all-night mission" to test the pressure of the tank at the center of the chemical leak, which contains methyl methacrylate, a highly flammable substance used in the production of plastics. McGovern said crews hoped to determine if a BLEVE threat, or Boiling Liquid Expanding Vapor Explosion, had been eliminated after a crack was discovered in the tank. 

"The BLEVE threat is the worst-case catastrophic event that we've been talking about," McGovern said. "We are not there yet; we need to run this operation tonight."

Earlier Sunday, McGovern said that he was hopeful additional tests would lead to the reduction of evacuation zones, but stipulated that such a decision would not be made until officials were absolutely certain that it was safe for the public to return to the area.