Abstract: At about 11:50 a.m. on January 28, 2008, a company was working to demolish several structures at the PG&E Hunter's Point power generation plant. Several employees were preparing for the controlled demolition of Boiler House # 6, a metal structure approximately 125 ft in height. The demolition plan called for the structure to be toppled to the west or southwest by failing three legs in a sequential manner from south to north. Soon after the final bottom leg cuts and before all the personnel and equipment were pulled out of the area, the structure collapsed prematurely. Employees #1 and #2 were in baskets of aerial devices and Employee #3 was in an excavator's cab. Employee #1 was killed. Employees #2 and #3 were hospitalized for fractures. The project engineer and the company's competent demolition person were at the site at the time of collapse. The competent person stated that he had been under the structure checking the work, but he left the site moments before the structure's collapse to retrieve equipment, and returned when the collapse occurred. The investigation revealed no incident-related violations. The cause of the collapse could not be determined. The demolition contractor had all required permits for the project from City & County of San Francisco and Cal/OSHA. The demolition plan was signed and stamped by a California Registered Civil Engineer. The work was performed under the immediate supervision of a knowledgeable qualified demolition person, as well as a registered engineer. All the employees working at the site, including but not limited to laborers, foreman, and the superintendent, had received training. Project safety meetings were held daily, and attendance was mandatory.