Authorities from the U.S. Occupational Safety and Health Administration were investigating at Progress Energy Florida's complex in Crystal River on Saturday, according to Progress spokesman Mac Harris. OSHA's investigation at the site follows Thursday night's accident at a coal-burning power plant that led to the death of plant operator William T. "Bill" Bowers of Yankeetown. Workers recalled that Bowers, 49, and a veteran of the company, was turning a wheel to open a pump valve and the valve exploded. Bowers died Friday afternoon at Tampa General Hospital. In addition to OSHA's investigation, Harris said Progress officials also are investigating to determine the cause of the accident.