http://www.cnn.com/2010/US/09/08/us.gulf.oil.disaster/index.html?hpt=T1&iref=BN1"Multiple companies and work teams" contributed to the April 20 explosion aboard the offshore Deepwater Horizon oil rig, unleashing the worst oil spill in U.S. history, BP's internal investigation of the disaster concluded Wednesday.
While BP said its team "incorrectly accepted" results of a negative pressure test aboard the rig before the blast, the internal report assigns much of the blame to rig owner Transocean.
"Over a 40-minute period, the Transocean rig crew failed to recognize and act on the influx of hydrocarbons into the well until the hydrocarbons were in the riser and rapidly flowing to the surface," the report states.
The explosion left 11 men dead and spewed millions of barrels of oil into the Gulf of Mexico over an 87-day period.
BP investigators found signs of "potential weaknesses in the testing regime and maintenance management system" for the blowout preventer that failed to shut down the well at the heart of the underwater oil gusher, the report said.
"The team did not identify any single action or inaction that caused this accident," according to the report. "Rather, a complex and interlinked series of mechanical failure, human judgments, engineering design, operational implementation and team interfaces came together to allow the initiation and escalation of the accident."