More than 40,000 people were evacuated in multiple Southern California cities on Friday after authorities warned that a leaking chemical tank at an Orange County aerospace facility remained in a dangerous condition and could potentially explode.
The leak began on the afternoon of May 21 from a 34,000-gallon storage tank containing methyl methacrylate, a plastic epoxy whose vapors can form explosive mixtures with air and are highly flammable when exposed to open flames or high temperatures. According to Orange County Health Officer Regina Chinsio-Kwong, inhalation exposure could cause "significant damage."