This was a little over an hour west of where we live. City is on severe water rationing now
There is only speculation at this point. From the wash out in the dirt from earlier pics, it looked liked there was still a good amount of water inside.Any idea on how much water was left in the tank??
And where the welding was being done on it??
It seems more probable that he was working on the water treatment end of the plant.
Chlorine is not flammable but will react violently under the right conditions.