A deadly blast at the headquarters of the Mexican state oil company Pemex was caused by a build-up of gas, the attorney general has said. Jesus Murillo Karam said no traces of explosives were found at the site in Mexico City. He said experts believed an electrical fault had caused a spark that detonated the leaking gas last Thursday. The death toll from the blast has risen to 37. Several lower floors collapsed in the explosion. More than 100 people are being treated in hospital, many of them injured by falling masonry.
Mr Murillo Karam said the source of the gas was still being investigated, although it is believed methane gas may have leaked from ducts beneath the building or from the sewer system. “There are several possible sources,” he added. “This explosion… generated an effect on the structures of the floors of the building, first pushing them up and then causing them to fall, and that was the primary cause of deaths in the building,” he said.