Abstract: At 1:45 p.m. on May 30, 2005, Employee #1 and Employee #2, working as part of a four-man crew, were drilling a new gas well. The drilling operations required the replacement of a lower spool when changing from 7-in. pipe to 4-in. pipe. A representative from another company delivered the replacement spool. At this time, the employees' supervisor left the work area and the representative directed the crew to remove the 18,000-lbs stack as one piece, in order to prevent disassembling the unit and to save time. The stack consisted of the spool to be replaced, a blowout preventer, upper spool and rotary head. Chains had been hooked to two of four attachments on the blowout preventer. The stack was lifted several times, and despite the lower spool being mostly unbolted, it was stuck to the blowout preventer. Employee #1 and Employee #2 were using pry bars to free the spool, when the top heavy stack fell over and struck both employees. Employee #1 was killed, and Employee #2 received multiple bruises but his injuries did not require hospitalization.