Rig survivors: BP ordered shortcut on day of blast

The morning the Deepwater Horizon oil rig exploded, a BP executive and a Transocean official argued over how to proceed with the drilling, rig survivors told CNN's Anderson Cooper in an exclusive interview. The survivors' account paints perhaps the most detailed picture yet of what happened on the deepwater rig -- and the possible causes of the April 20 explosion. The BP official wanted workers to replace heavy mud, used to keep the well's pressure down, with lighter seawater to help speed a process that was costing an estimated $750,000 a day and was already running five weeks late, rig survivors told CNN. BP won the argument, said Doug Brown, the rig's chief mechanic. "He basically said, 'Well, this is how it's gonna be.' " "That's what the big argument was about," added Daniel Barron III