The Tank is the biggest and strongest of all the Infected and is reasonably fast, only slowing if hit with large amounts of automatic weapons fire or when lit on fire (Versus in Left 4 Dead only and any mode aside Versus on Left 4 Dead 2). He is the only player-controllable "Boss Infected." If any Survivors at 40% or above health (including health gained from Pain pills or the Adrenaline Shot) are running away from the Tank, it will not be able to catch them, as they can run slightly faster (unless the Tank in question is an AI Tank in Left 4 Dead). The Tank has incredible strength and resistance―his punch can send Survivors flying, rendering them temporarily defenseless, and in Expert mode, instantly incapacitate them. The blow can send Survivors off high hazards to their deaths. He is also capable of throwing chunks of concrete that he rips out of the ground to momentarily stun Survivors and dealing the same damage as a punch from a Tank. It can also punch large objects in the direction of Survivors with enough force to incapacitate them instantly. Nevertheless, the Tank will die within 30 to 45 seconds if set on fire (varying with the difficulty), except in Versus. When controlled by a player, the Tank has a "Control Meter"; unless the player is able to locate the Survivors and hit one of them, the Control Meter of the Tank will slowly lessen, and once it runs out, the player will lose control of the Tank to another randomly assigned player. When idle, the sound that a Tank makes is heavy breathing. The Survivors are alerted of an approaching Tank by dramatic music, furious roars and, when he is dangerously close, the screen will start to shake.