Emergency crews in Garden Grove, Orange County, are engaged in an urgent and ongoing operation to prevent a potential explosion at an aerospace facility where a pressurized tank containing a toxic chemical has been steadily overheating.

Authorities warned that the situation could lead to a BLEVE—boiling liquid expanding vapor explosion—a worst-case scenario that could cause catastrophic damage if the tank fails under pressure.

Officials reported that the tank’s temperature reached 100 degrees Fahrenheit, which is the maximum reading available on the gauge, indicating a continued upward trend from 90 degrees on Saturday and 77 degrees on Friday.

The primary objective of responders is to reduce the internal temperature to around 50 degrees to eliminate the risk of thermal runaway and explosion.

Firefighters and hazardous materials teams have launched what officials described as an “all-night mission” to determine whether the tank’s pressure can be safely relieved.A possible crack detected in the tank has raised cautious optimism, as it may be releasing pressure and lowering the risk of an explosive failure.However, officials stressed that the danger has not yet passed and evacuation zones remain in place to protect residents and responders.The U.S.Environmental Protection Agency has suggested the most likely outcome may be a low-volume controlled release, which could be managed and neutralized.Despite some signs of progress, authorities continue to monitor the situation closely and emphasize that conditions remain volatile.

Officials have not disclosed the precise temperature threshold that would trigger an explosion, underscoring the uncertainty surrounding the tank’s stability.

The next several hours are considered critical as crews work to stabilize the chemical system and prevent a potentially devastating industrial disaster in the densely populated region.