The first explosion ripped through the Deepwater Horizon's drilling floor at 9:49 p.m. on April 20, 2010, when "a jet engine's worth of gas" flew from the well, a Transocean representative told an investigating commission.
The rig had reached the well's "pay zone," 18,193 feet below sea level, and was preparing to seal the well for later oil production. Several investigations have attributed the accident to errors of varying scale, by BP, government regulators, Halliburton, Transocean, and others.
Fire-boat response crews still battled the blazing remnants of the Deepwater Horizon in the Gulf of Mexico on April 21. It sank the next day.
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