California authorities are racing to prevent a damaged chemical tank at the GKN Aerospace plant in Garden Grove from exploding after discovering a crack that may be releasing pressure, while over 50,000 residents remain under evacuation orders.

LOS ANGELES, May 25 (Xinhua) -- California authorities said on Sunday that a potential crack was found in a damaged industrial tank containing volatile chemicals in Orange County as emergency crews raced to prevent the tank from rupturing or exploding.

Orange County Fire Authority (OCFA) Interim Fire Chief TJ McGovern said his team conducted an operation Saturday night to visualize the tank, noting that the discovery of a crack in the tank "could potentially be relieving some of the pressure in there."

He also said this intel "could change the mission's trajectory," underscoring that the development was a "step in the right direction."

To clarify reports claiming there are multiple cracks on the tank, OCFA confirmed that there is only one known crack.

"There is also peeling of the weather stripping on the exterior, but this is not an additional crack," said OCFA, adding that currently, no active chemical leak has been detected.

In a Sunday evening update, McGovern said that emergency crews would conduct an all-night mission to confirm whether "the pressure in the tank has been released and the BLEVE (Boiling Liquid Expanding Vapor Explosion) threat is eliminated."

The tank at the GKN Aerospace plant in Garden Grove, which contains methyl methacrylate, a highly flammable industrial chemical used in aerospace manufacturing, has remained at an unstable temperature for days.

The situation has grown more urgent as temperatures inside the compromised tank have continued to rise, reaching about 90 degrees Fahrenheit (32.22 degrees Celsius) on Saturday from 77 degrees (25 degrees Celsius) a day earlier.

A heavy, constant flow of water has been used to try to cool the outside of the tank. However, at last check on Sunday, officials said the internal temperature of the tank was over 100 degrees (37.78 degrees Celsius).

Authorities pointed out that the situation was still dangerously volatile, and evacuation orders remain in place for more than 50,000 residents in six Orange County cities, namely Garden Grove, Cypress, Stanton, Anaheim, Buena Park and Westminster. Public health officials urged residents to continue obeying evacuation orders.

Officials said air quality monitoring outside evacuation areas had not detected dangerous contamination levels, with no injuries reported.

California Governor Gavin Newsom on Saturday declared a state of emergency in Orange County and submitted an Emergency Declaration request to President Donald Trump to support ongoing response operations in the County.