Mr. Morrison listed five near-miss incidents in November and December, including one in which natural gas escaped from a pipe aboard BP's Pompano platform, threatening an explosion.
As early as five hours before the explosion drillers noticed unexpected loss of fluid in the riser pipe, indicating leaks in a part of the blowout preventer.
At 8:20 p.m. on the day of the explosion the pressure data suggest there was a constant flow of sea water being pumped into the drill pipe that was displacing the heavier mud system which was the primary pressure control for the well.