Abstract: On April 4, 2002, Employees #1 and #2 were working together on removing liquid perchloroethylene from a 9.3-foot-high vapor degreaser. The interior of the degreaser was a permit required confined space. Employee #1 entered the degreaser from the top, standing on an interior ledge located 3 feet from the top opening. Employee #1, wearing only a paper mask as respiratory protection, was to assigned to position and use a cylindrical piston pump 53 inches long inside the degreaser to pump liquid perchloroethylene out of the latter. Employee #1 fell to the bottom of the degreaser. Employee #2, who had been standing on the floor outside the degreaser, then climbed on the degreaser, broke the plane of entry, and stood on the interior ledge with the intent of rescuing Employee #1. Another coworker joined Employee #2 on the interior ledge when he heard a scream. By the time the coworker reached Employee #2, they were unable to rescue Employee #1. Also, Employee #1 was unable to exit the vapor degreaser on his own. The coworker retrieved Employee #2 and exited the degreaser. Fire department personnel rescued Employee #1. The batch vapor degreaser was manufactured by Baron-Blakeslee. The model Number was dp-72/36. The dimensions were 3 inches to 8 inches wide by 6 feet to 6.5 inches long by 9 feet 3 high. The degreaser had a 30 kw electrical sump heater, a secondary chiller, a pressurized air operated roll top cover, and a freeboard ratio of 1.0. Employees #1 and #2 were overcome by exposure to airborne perchloroethylene. Employee #1 was hospitalized overnight in a critical care burn unit. Employee #2 was released from hospital within 24 hours.