Potential crack in Garden Grove chemical tank could be easing pressure, officials say

GARDEN GROVE, Calif. — A potential crack in a Garden Grove storage tank holding toxic chemicals may be relieving internal pressure that authorities had feared could lead to a rupture or explosion, Orange County fire officials said Sunday.

Nearly 50,000 residents remain under evacuation orders as a specialized response team continues to assess the tank, which contains methyl methacrylate, a highly flammable industrial chemical. Gov. Gavin Newsom declared a state of emergency Saturday.

A specialized team accessed the tank Saturday night and identified the crack, said TJ McGovern, interim chief of the Orange County Fire Authority.

"We got data on it, and right now this morning, what we're doing is we are vetting and validating that information," McGovern said. "With this new information, it could change our trajectory and our strategy to this event."

The discovery followed reports a day earlier that the tank's internal temperature was climbing — a development that had heightened concerns of catastrophic failure.

Craig Covey, an Orange County Fire Authority division chief serving as incident commander, said crews are using drones to monitor the tank around the clock.

"We're continuing to keep them cool and monitor them," Covey said Saturday. "We've got the drones on them — every 10 minutes watching for any temperature changes or spikes."

Covey said additional resources are arriving from across the country as officials prepare contingency plans to protect surrounding neighborhoods and waterways in the event the tank fails.

The Orange County District Attorney's Office has opened an investigation into the incident, which involves GKN Aerospace. Prosecutors have set up an anonymous tip line — 714-347-8714 — seeking information about maintenance frequency and industrial operations at the site.