A look back at PEPCON 38 years after explosion — PHOTOS

The Pacific Engineering and Production Company of Nevada, known as PEPCON, was destroyed 38 years ago in a series of explosions after ammonium perchlorate, an oxidizer used in rocket fuel, caught fire.

The Review-Journal previously reported that approximately 4,500 tons of ammonium perchlorate was being stored at the plant on the day of the blast, May 4, 1988. During the blast and subsequent fire, 1,500 tons of ammonium perchlorate were consumed — four times the amount of the oxidizer used for one space shuttle solid rocket booster.

The fire was caused by a welding torch that ignited a structure at the plant. The fire spread to several nearby 55-gallon drums of ammonium perchlorate. About 20 minutes later, the first explosion occurred at 11:52 a.m., followed by the second explosion four minutes later. The fire after the explosions burned for five hours, according to a NASA report.