Three workers are in critical condition with burns after the barge they were cleaning exploded. No one has said if the workers were inside the barge when it exploded; but from the visual damage I would say they were not inside it but most likely on top of it. The barge(s) last held a flammable liquid called “natural gasoline” and were being cleaned at the time of the accident. Natural gasoline is a volatile natural gas product with an octane rating between 30 and 40. Natural gasoline was used as an early automotive fuel, but is used in the present day as a feedstock for gasoline, paint thinner, solvents and cleaning products. US Coast Guard officials have said the cause of the explosion was a spark that was generated during cleaning.