I question the accuracy of your statement. Do millions of children find violence in school every day?
In the 2006-2007 school year, there were approximately 64 million students in grades K through 12 in the US.
When you say "millions," how many of these 64 million do you mean? How will you prove that?
I think, and I believe Ms. Sue will agree, that you have an untenable statement. You need to re-think what you really want to say.
Your thesis statement must include factual information plus your position/opinion/stance. Without your position on the topic, it isn't a true thesis statement. So think of this sentence as the angle you want to take on the topic and what you intend to prove by the end of your paper. (If your statement is simply factual, then there's nothing to prove!)
This is one of the very best places I've seen online to help students write good thesis statements. It shows you sentences that aren't thesis statements and how to turn each one into real thesis statements.
Actually, I disagree with Writeacher. I think you did write what you wanted to say, however, I do agree it is silly, ill-thought out, and fodder for shallow thinkers.
The purpose of education is to sharpen our analytic and communication skills. In doing that, we sharpen the words we use to avoid vagueness and shallow analysis.
Finally, I wonder just what you mean by "violence"...that in itself is an ill defined word.