Andrea Luna, Jules Olivas, Joshua Olivas and Jessica Castro of Anaheim, Calif., shelter in their cars at the John F. Kennedy High School evacuation center on Saturday after leaving their home due to a chemical leak from a storage tank at the GKN Aerospace facility in Garden Grove, Calif. A failing 34,000-gallon tank of methyl methacrylate overheated, prompting tens of thousands of evacuations in the Garden Grove area. Photo by Ted Soqui/EPA

May 24 (UPI) -- Tens of thousands of Orange County, Calif., residents remained evacuated Sunday as officials nervously watched the condition of a failing, 34,000-gallon tank containing dangerous chemicals.

Orange County fire officials said a visual inspection of the overheated tank in Garden Grove, Calif., late Saturday showed it has potentially developed a crack, which could reduce the possibility of a catastrophic explosion but increase the likelihood of a massive spill of liquid methyl metacrylate.

"Right now, we're vetting and validating that information," Orange County Fire Authority Interim Chief T.J. McGovern said in a video update of the tense situation at the GKN Aerospace facility, located about 33 miles southeast of downtown Los Angeles.