I'm looking for a movie?

This is a movie that came out in the last 5 years or so(i think) but a group of assassins/killers get trapped in their base due to a lock down. But in the process a self destruct was placed on the base and the one person who had the codes was killed, so everyone starts killing each other. Only other thing I can remember was that the secret enterance to the base was behind the wall by the water dispenser..