Abstract: At approximately 10:02 a.m. on February 4, 2004, Employee #1 was found unresponsive at the bottom of a trailer tank, which previously held silicon tetrachloride. Employee #1 had been assigned to prepare the tank for a required inspection with a contractor service. When the foreman could not locate Employee #1, he climbed the ladder and looked into the confined space opening. He saw Employee #1, so he entered the tank to rescue Employee #1. Employee # 1 was pronounced dead at approximately 10:30 a.m. after the resuscitation attempts failed. Oxygen contents at the bottom of the tank were approximately 12 when measured by emergency services. The tank, which was previously cleaned and purged with nitrogen, was not ventilated. The cause of death determined by the medical examiner was asphyxiation due to vitiated environment.