BP Investigator: 8 Failures Led to Disaster

The lead BP PLC investigator is saying that eight separate failures had to occur for the company's deepwater well to unleash the largest offshore oil spill in U.S. history.

At a briefing in Washington Wednesday on BP's internal investigation, Mark Bly, the chief investigator, told reporters that all eight things needed to happen to cause the accident. The failures included cement that did not prevent oil and gas from entering the well and a blowout preventer that did not seal off the well.

Bly also said that while the company's report was clinical and fact-based, the investigative team had "a very strong emotional feeling about the accident."

Special Section: Disaster in the Gulf

In its 193-page report posted on its website, the British company described the incident as an accident that arose from a complex and interlinked series of mechanical failures, human judgments, engineering design, operational implementation and team interfaces.

BP's Deepwater Accident Investigation

BP spread the blame around, and even was critical of its own workers' conduct, but it defended some parts of the well's design and it was careful in its assessments. It already faces hundreds of lawsuits and billions of dollars of liabilities. In public hearings, it had already tried to shift some of the blame to rig owner Transocean Ltd. and cement contractor Halliburton. BP was leasing the rig from Transocean and owned the well that blew out.

While BP didn't completely absolve its engineers, the company shot down some of the things they've been criticized for by members of Congress and others.

"Well control actions taken prior to the explosion suggest the rig crew was not sufficiently prepared to manage an escalating well control situation," the report said.