How does a traumatic amputation in a car accident occur?

Question

Yes, I know this sounds a little morbid, but I'm curious about the biology behind it. Today in LA a street race resulted in the death of three young people, and two others, one of whom had his leg ripped off at the hip. According to eye witnesses, one of the dead was, I guess, torn in half. So, how exactly does this happen? Is it caused by the seat-belt cutting the person in half? The reports say "blunt force," but I don't understand what that is--unless a blunt object--like a tree---comes into the car, how does blunt force occur?

Answer 1

There are two types of trauma- sharp, like a knife and blunt force.  In the case of a car crash, since I only have what you related to go on, I suspect that the guy who was amputated at the hip probably ended up with the engine coming through into the passenger compartment and landing through his hip.  That is blunt force trauma.  Having your leg stuck out the door and then having the car turn over on the leg is also blunt force trauma.

Basically it happens when something big and heavy shears off a body part.  It's a mechanical issue, not biological.  Force and velocity and inertia on a body made of flesh and bone means that usually the body is  the loser.  One thing is sure- it's not pretty.