Crews investigating if OC chemical tank pressure has been relieved after crack discovered

The Orange County Fire Authority says the internal temperature of an unstable chemical tank at GKN Aerospace is now over 100 degrees.

The Orange County Fire Authority says the internal temperature of an unstable chemical tank at GKN Aerospace is now over 100 degrees.

Officials don't know how far over 100 degrees the temperature has climbed because the gauge doesn't read higher than 100, the OCFA said.

Eyewitness News asked what temperature would trigger an explosion, but the OCFA did not have an answer. Despite the temperature, officials say they do not believe there are any contaminants currently leaking from the tank.

At one point on Saturday, OCFA officials said the temperature of the tank was rising by about one degree per hour. The tank was 77 degrees on Friday morning.

Firefighters are hopeful that the discovery of a crack in the tank on Saturday night will relieve some pressure, leading to a more favorable outcome.

"So far, it's been positive news because there is no vapors being detected by the air monitors, and there is no active leak that is on the ground. So far, that is a good sign," said Capt. Brian Yau with OCFA. "The next determination is the pressure behind this, because it has expanded. The tank has expanded, and it has cracked. So what is causing it? We need to figure out what is causing the expansion and the cracking of the tank."

Officials say if the external temperature of the tank stays in a low zone, around 50 degrees, it means the ground monitors are effective in keeping the tanks cool. On Sunday evening, officials said the external temperature was around 60 degrees.

OCFA is reiterating the importance of leaving if you are within the evacuation zones. Officials said they noticed some people returning to their homes on Sunday, but they stressed that the evacuation order is in place for everyone's safety.

A crack discovered in a chemical tank is now offering a glimmer of hope, but what exactly does it mean?

OCFA Interim Chief T.J. McGovern explained to ABC News Reporter Jaclyn Lee that teams executed an operation late Saturday night to get eyes on the tank. To their surprise, they discovered the crack.

Lee: "Why would this be a good thing?"
McGovern: "So the thing about the crack is what we're looking for, it's going to relieve pressure. We want the pressure relieved out of that tank."

When asked if a crack could hypothetically lead to a larger leak, McGovern said they are using drones and monitoring the air. He said they have complete confidence that there are no leaks.

Lee: "So the crack could mean no explosion?"
McGovern: "Not necessarily. The crack with the relief of pressure could be there is no BLEVE. There could still be an explosion. The explosion could be caused by the material in there. It'd be an explosion. Explosion is much lesser than an actual BLEVE."

BLEVE stands for Boiling Liquid Expanding Vapor Explosion and in simple terms, there could still be an explosion, just a smaller one than initially feared.

McGovern said teams will conduct another mission Sunday night to confirm information about the crack and if the data is positive, they will likely decrease the size of the evacuation zone.

Gov. Newsom submitted a request for an emergency declaration to President Donald Trump to support ongoing response operations in Orange County.

Gov. Gavin Newsom submitted a request Saturday night for an emergency declaration to President Donald Trump to support ongoing response operations in Orange County.

"California doesn't wait for disaster to unfold, we act early to protect lives and communities," Newsom said. "Working together with our local and federal partners, we're strengthening our ability to respond quickly and effectively in Garden Grove and across the surrounding communities and ensuring that first responders have the resources they need to keep people safe."

An emergency declaration is a formal action that allows the federal government, through FEMA, to help state and local governments with resources and funds to help with evacuations, shelters, emergency medical services and other operations to keep the public safe.

On Sunday, Senators Alex Padilla and Adam Schiff, along with Congressman Derek Tran, sent a letter to the president urging quick approval.

The Los Angeles Angels said Sunday night's game against the Texas Rangers will proceed as scheduled amid the ongoing chemical tank investigation.

"We are closely monitoring the ongoing situation and remain in contact with local officials," read a statement from the Angels organization. "At this time, there are no changes to tonight's scheduled game against the Rangers."