Car won't accelerate nor will it turn

My car has only done this twice. It seems to do it right
after I hit a speed bump. I can come to a stop, but when I
go to accelerate and/or turn, my car just won't. I'm not
able to turn my wheel at all. It locks up. I'm also not able
to go forward nor backwards. I tried to put it in park then
drive again, but nothing happens. The only way to make it
stop is to cut the car completely off, then start it again.