it can happen in an instant. a large crowd of people starts to surge and before you know it you're caught in a human stampede. in september of 2015, a crowd crush at the religious hajj pilgrimage to mecca kills 2400 people. in the u.s., stampedes can explode at sporting events, rock concerts, even black friday sales. and once mob rule takes over, it can be hard to know what to do. >> being in a crowd crush is so terrifying because there's a lack of ability to move or make decisions or do anything for yourself. you are at the mercy of the crowd. >> june 2010, nearly 200,000 people pile into the los angeles coliseum for the two-day electric daisy carnival.