Updated

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 history.

At a briefing in Washington Wednesday on BP's internal investigation, Mark Bly, the chief investigator, told a room of 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.

The company's presentation at a downtown hotel was expected to last 90 minutes.

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."