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