At approximately 1:00 p.m. on the 23rd October 1989 Phillips’ 66 chemical complex at Pasadena, near Houston (USA) experienced a chemical release on the polyethylene plant. A flammable vapor cloud formed which subsequently ignited resulting in a massive vapor cloud explosion. Following this initial explosion there was a series of further explosions and fires.
The consequences of the explosions resulted in 23 fatalities and between 130 – 300 people were injured. Extensive damage to the plant facilities occurred.
If you are at all interested in learning the root cause, contributing factors and corrective actions I suggest you do google search. There is very informative stuff written about this tragedy available for the asking.