As the crowd reaches the exit in the running scenario, they form a large wedge-like mass around the exit, restricting evacuation to all but a trickle. Like a mosh pit at a Pantera concert, the frenzied crowd compresses and expands, resulting in high pressure areas and serious injuries. In the walking scenario, the area still gets congested but the gridlocked crowd directly in front of the exit is less dense; the herd is more like the head-bobbing fans at the back of the auditorium, exerting less pressure on each other and causing fewer injuries.