From our colleagues at the Center for Public Integrity:

The Coast Guard grasped the potential threat of a catastrophic spill within hours of the April 20 explosion aboard 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.

The logs, obtained by the Center for Public Integrity and shared with The New York Times, provide a detailed account of the early days of the BP disaster and identify events that were omitted from the White House’s official timeline of the crisis.

The hour-by-hour documents reveal that first responders almost immediately understood the environmental threat to the Gulf of Mexico after the rig exploded and Coast Guard officials detected the first signs of oil appearing on the water on the morning of April 21.

Officials also learned within the first day of the disaster that the blowout preventer — an oil rig safety device that is supposed to cut off a well in case of an accident — was not functioning and could not be manually repaired by remote underwater robots.

The official White House timeline makes no mention of the early spill estimates or the failed attempts to repair the blowout preventer. It first acknowledges a leak on April 24, four days after the explosion, when undersea robots discovered a plume of oil coming from the riser on the sea floor.

Full report is here, logs are here.