The U.S. Chemical Safety Board will investigate the root causes of the BP Deepwater Horizon blowout accident.

On April 20, a sudden explosion and fire occurred on the BP/Transocean Deepwater Horizon oil rig. The accident resulted in the deaths of 11 workers and caused a massive, ongoing oil spill into the Gulf of Mexico. The rig was located approximately 50 miles southeast of Venice, La., and had a 126-member crew onboard. CSB's investigation is currently underway.

CSB Chairman John Bresland formally announced the launch of the investigation in a letter to Rep. Waxman and Rep. Stupak, chairmen of the U.S. House Committee on Energy and Commerce, saying in part:

I write in response to your letter of June 8, 2010, requesting a CSB investigation of the causes of the BP/Transocean rig explosion that occurred on April 20, 2010. We recognize that this human and ecological disaster is one of the most significant chemical accidents of the current era. We also agree, as noted in your letter, that the CSB’s past work on BP’s safety culture and corporate safety oversight places us in a unique role to understand important aspects of this tragedy...

For ... these reasons, the CSB intends to proceed with an investigation of the root causes of the accidental chemical release that destroyed the Deepwater Horizon rig and took the lives of 11 workers. The investigation will include the key investigators who were involved in the CSB’s 2005-2007 investigation of the March 23, 2005, explosion at the BP Texas City refinery. We intend to prioritize this work and to apply all of our available resources to ensure the best possible investigation.

Both letters and the CSB's preliminary plan to staff and fund the investigation are available on