Authorities braced for the possibility that a damaged chemical tank in Southern California could leak or explode as an evacuation order continued into the Memorial Day weekend for 40,000 residents with no timeline on when they can return. No injuries were reported after the pressurized tank overheated Thursday and began venting vapors at a company site in Garden Grove, about 40 miles (60 kilometers) south of downtown Los Angeles, according to the Orange County Fire Authority.