The leak was caused when a large amount of water entered the MIC storage tank. Water reacts with MIC in an exothermic reaction that quickly raised the temperature and pressure inside the tank that overwhelmed the safety valves. Investigations into the accident highlighted many problems involving poor safety maintenance, cost cutting, and ignored warnings. The plant is shut down, but still poses a toxic danger zone that is in need of cleaning up 25 years later.
Find out what else occurred on this day in science history.