Tenant Water damage issue

[Blake Reynolds]

HI all, 

Here is my question/concern. I currently own a town-home which I live in and rent out the 2 spare bedrooms. Recently one of my roommates flooded the toilet in the upstairs bathroom and now there is damage to the ceiling Sheetrock on the floor below the bathroom. Am I justified in using his security deposit to repair the damages? He did admit to me that it was him that caused the overflow. 

I am having my homeowners insurance to come out and see if it is covered and to give me a quote on the repairs. I have never had to deal with a situation like this before so I am curious what the best way to handle this would be.