An investigation by Center for Public Integrity reveals surprises about the worst oil spill in US history:

Coast Guard officials grasped the potential threat of a catastrophic spill within hours of the explosion on board the Deepwater Horizon drilling rig, estimating that 8,000 barrels a day of crude oil could possibly gush out of the well in the event of a complete blowout, according to Coast Guard logs.

Over the first three days of the crisis — long before the public heard of a leak — the minimum estimate for a total well blowout ballooned eight-fold and the president was warned by his top aides that a major spill larger than the 1989 Exxon Valdez might be coming, according to the documents and interviews.

The logs, obtained by the Center for Public Integrity, provide the most detailed account of the early days of the BP disaster, and identify key events and notifications that were omitted from the White House’s official timeline of the crisis.

The estimate of the potential leak on April 21, the day after the rig exploded, reveals that first responders almost immediately understood the environmental threat to the Gulf of Mexico when Coast Guard officials detected the first signs of oil appearing on the Gulf waters.