High Quality Content by WIKIPEDIA articles! On 22 April 2010, the United States Coast Guard and the Minerals Management Service launched an investigation of the possible causes of the Deepwater Horizon oil spill explosion. On 11 May the Obama administration requested the National Academy of Engineering conduct an independent technical investigation to determine the root causes of the disaster so that corrective steps could be taken to address the mechanical failures underlying the accident. On 22 May President Obama announced that he had issued Executive Order 13543 establishing the bipartisan National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling, with former Florida Governor and Senator Bob Graham and former Environmental Protection Agency Administrator William K. Reilly serving as co-chairs. The purpose of the commission was to "consider the root causes of the disaster and offer options on safety and environmental precautions." On 1 June, U.S. Attorney General Eric Holder announced that he opened an investigation of the oil spill. According to Holder, the Justice Department would be interviewing witnesses as part of a criminal and civil investigation. Besides BP, the investigation could apply to other companies involved in the drilling of the damaged well.