5:35 P.M. UPDATE - WYXC-AM reporter John Underwood says that the explosion took place in a cooling tower. There are reports that there are holes in the cooling towers.Some people nearby said that airbags in their vehicles near the plant were set off by the explosion.
There have been no reports of casualties.
Buildup of some flammable gas inside the tower finds an ignition source?
Some gas that's used in water treatment, maybe?
Whole lotta volume in those things. That concrete is pretty thin in places. The strength is in the top and bottom rings.