How do crocodile kill their prey?

Crocodiles (and Alligators) - are 'ambush' predators. They lie in wait submerged near the water's edge, and grab any 'prey' animal that gets too close. The victim is usually dragged into deeper water, where the crocodile performs a 'death roll'. This is done with enough speed, and force - that the prey normally suffers a broken neck.