Chevrolet 2005 Silverado 1500 Pickup Owner's Manual page 28

Q:
What is wrong with this?
A:
The belt is twisted across the body.
1-22
CAUTION:
{
You can be seriously injured by a twisted belt.
In a crash, you would not have the full width of
the belt to spread impact forces. If a belt is
twisted, make it straight so it can work
properly, or ask your dealer to fix it.
To unlatch the belt, just push the button on the buckle.
The belt should go back out of the way.