The April 17, 2013, fertilizer-plant explosion in West, Texas, that killed 15 and demolished a good part of the town was only the most recent of a number of accidents involving hazardous chemicals that have happened in Texas over the years. Home to a large number of refining and petrochemical plants and other high-tech industries, Texas has had more than its share of explosions, fires, leaks of toxic and polluting chemicals, and other chemical-related accidents.

But when reporters from The Dallas Morning News tried to get an answer to what they thought was a simple, straightforward question about the frequency of chemical accidents, they found a mare’s nest of conflicting and incomplete statistics. Is this a basic problem that leads to a higher rate of accidents than we would normally have? Or is it just an inherent difficulty that occurs because of the nature of chemical accidents?

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