Something is wrong with my car's steering?

This is a little hard for me to explain. But think of it like this: When I go straight, my steering wheel is normally facing "north."

Today (out of the blue) straight just became "west" That is to say that to make my car go straight I had to hold my steering wheel the way I would normally to make a left hand turn.

I didn't hit anything, and I didn't hear any terriable noises.
What could this mean?

thanks so much. By the way, this is a 1997 Buick Lesabre.
 
Back
Top