We were behind a vehicle that had come to a rolling stop because the vehicle in front of him had hit the person in front of him , we were going about 25 miles per hour and about 2 car lengths from him . I applied the brakes but the vehicle failed to stop . It was as if I did not press the brakes at all. We rearended the person in front of us . The person behind us hit us as well . It was like we were on ice but we were not .