I was misinformed by my Sgt. It was not a field piece, just a bazooka and the NG only fired three bazooka rounds killing no one, but they did start the assault by sticking a Thompson sub-machine gun in a cell where the riot leaders were thought to be and spraying some rounds. And a Highway Patrolman did that- I guess they do accomplish more than write speeding tickets.
I like my Sgt's version better. He was telling me about the riot as we drove by the damaged and patched wall section after delivering a prisoner to the new MSP facilty west of town.
Some of the Wiki history reads like Shawshank Redemption.