How do colleges look at volunteer firefighters?

I want to go to either Yale, Vanderbilt, Cornell, Emory, or Rice. I received a D+ in my AP Statistics cl (which was during my sopre year) because I took on more than I could handle. However my GPA is a 3.9. I am taking really challenging cles. My SAT scores are pretty alright; they are above normal. What are my chances of getting into those colleges? If you want more information, just ask.