Strange/bad noise from brakes?

[Viper3812]

I was driving back from work and I hear this wierd high pitched sound coming from somewhere on the car. I put the car in reverse and nothing happens, but when I put the car in drive I hear this loud, high pitched grinding sound which I think is coming from the brakes. Anyone know what this might be or have had this problem before? I'm trying to take off the wheel right now to take a look, but it's taking some time. I got all of the lugs off except one and thsi one is a on really tight.

[Viper3812]

Just figured out my problem. They repaved my neighborhood and there are a bunch of little rocks around the street so one of them must've jumped up and landed in between the hub and rotor.