if my kid was hurt because of a 200:1 ratio, yeah, I probably would sue. That's way beyond a lot of kids, that's just not caring. But I suppose that's an extreme number, and hope it's not really true anywhere.
As to what I'd really do in a more reasonable situation, funny story....
When my oldest was 5, the school called me a couple times. (this'd be the school that told me my now-assessed-as-gifted-son is retarded). Seemed Zach had decided in his wisdom a couple times during lunch to start home instead of staying in the yard. When they finally called, wanting me to punish him and deal with it, he'd done it 6!! times. So six times there was a search party out for my kid, and noone told me. But that's not my point here. I was upset at first, and talked to him, and then find out a couple days later, he'd done it again!!! And it dawned on me, he's FIVE! wtf are they doing not watching that he's not exiting the schoolyard? If I knew he had a propensity to do something dangerous at home and didn't take care that he didn't, I'd be charged with neglect. So I called the school. And they told me that there was no way they could supervise that many children at once, and it was Zach's (WHO IS FIVE) responsibility. So, I lost it. And called the superintendent of schools. And the school got reprimanded, and they had to hire more "watchers". I got a call from the principal a few days later, "we know what you did, Mrs. Summerton"