"We've had an explosion and everything's on fire" Company Comptroller Roy Westerfield  told a dispatcher.  A few seconds later he said "Get 'em all out of here". 

These were quite possibly his last words.

On May 4th, 1988, a loud explosion rocked the entire Southern Nevada Valley.  The ground rumbled, windows shook and, in many places, shattered completely.  Residents at first thought it was an earthquake.  Others who saw a mushroom cloud rising over  Henderson thought a nuclear nightmare might be unfolding in the industrial city.

In reality, it was an industrial disaster that occurred  at the Pacific Engineering Production Company of Nevada which was commonly referred to as PEPCON.  The plant, located in Henderson, was one of two American producers of ammonium perchlorate which is an oxidizer in solid rocket fuel boosters for the Space Shuttle and the military's Titan Missile  program.

The other American manufacturer, Kerr-McGee, was located less than five miles away from the PEPCON plant and well with-in the area that suffered blast damage.