All right, then. Here's more to consider. The explosions were only shaped charges to puncture the tanks to allow the drainage of the vinyl chloride. They took measures to trap the liquid and set it afire. The combustion products of vinly chloride are phosgene and hydrogen chloride. Phosgene is a poison gas and hydrogen chloride, when inhaled, will form hydrochloric acid in the lungs. Now, as bad as this sounds...it was not as bad as allowing the vinyl chloride to be released by itself. Think about that. Sometimes, the only choice available is between terrible bad and not-as-terrible bad. What would you do differently? What COULD you do differently?

I am not too impressed with the problems of "convincing" ignorant "anons" of the correctness of facts. I don't think anything I have said is "conjecture." The facts of the case have been disclosed. The facts of chemistry are available with a little search in Wikipedia. If the tanks were in prospect of failing from the derailment damage, it sounds like letting the vinyl chloride simply leak out and dissipate was a non-starter.

And there have been worse industrial accidents (e.g., Bhopal, India), so get a sense of perspective. It's not good. It could have been handled better. It sounds like the responsible parties are trying to cover it over. But there are no obvious alternatives to what they thought they needed to do for the sake of reducing risk.