Nothing they said about what happened makes any sense at all. The symptoms described are chlorine gas symptoms, and one of the firemen said the chemicals were "bubbling up", but much of the rest of what they say seems to contradict that. My over all impression is that no one on site actually knew what was happening.
Trying to put the pieces together so they make sense, and therefore ignoring about half of what they said, I suspect they had high flow rate injectors for both bleach and muriatic acid setup so that only one could feed at a time. If something broke somehow (because of the storm???) so that both bleach and acid were feed in at the same time, that could create chlorine gas. But for that to happen the injection rates would have to be pretty high, higher than would normally make sense. But 9/10ths of this is guessing. The story is just too garbled.
