The Environmental Protection Agency chief on the job during the Exxon Valdez oil spill in Alaska in 1989 and a former Florida senator will lead the presidential commission investigating the Gulf of Mexico disaster. President Barack Obama on Saturday announced the appointments of William K. Reilly, EPA administrator under Republican President George H.W. Bush, and Bob Graham, a Democrat who also was Florida governor, as the panel's heads. Obama intends to name five others to the commission, which will examine issues such as what caused the spill, the safety of offshore drilling and operations at the Minerals Management Service, the federal agency that grants drilling rights. A report is due in six months. "I can't think of two people who will bring greater experience or better judgment to the task at hand," Obama said in his weekly radio and Internet address.