PEPCON EXPLOSION May 4, 1988, Henderson, Nevada.

The Pacific Engineering and Production Company of Nevada (PEPCON) was a facility that manufactured an oxidizer named Ammonium Perchlorate, which was used in solid rocket booster engines. This video explains what happened on My 4, 1988 when two massive explosions completely destroyed the facility.

Here is a link to a video that captured the two giant explosions:

Pepcon Explosion: Real Audio + Audio ...