if a car crashes into a lake, why is it so hard to open the doors?

Question: if a car crashes into a lake, why is it so hard to open the doors?
- Keywords:
  car,
  crash,
  door,
  lake,
  pressure,
  water
Asked by chickenmunch to Drew on 21 Jun 2011.
- Drew Rae answered on 21 Jun 2011:
  
  Chickenmunch. The pressure of the water outside is greater than the pressure of the air inside. You are pushing against all this pressure to open the doors. That’s why if you let the car fill up with water, it is then much easier to open the door, because the pressure is equal on each side.

Question: if a car crashes into a lake, why is it so hard to open the doors?