Guardian: Oil executives ignored warning signs in the hours before the disastrous Deepwater rig explosion in the Gulf of Mexico last month, a congressional hearing heard today. In a second day of hearings, the House of Representatives’ energy and commerce committee said documents and briefings suggested that BP, which owned the well; Transocean, which owned the rig; and Halliburton, which made the cement casing for the well, ignored tests in the hours before the 20 April explosion that …