My Dad's '57 Windsor did that when it was only a few years old. First one side and then the other a year or so later. The broken torsion bars were around and used as pry bars for many years.
The funniest was a '63 Dodge 330 I had. It was a little rough around the edges, but a decent car. My oldest son was about 7 years old at the time. I was standing in the garage and he had just walked up the driveway to check the mail. I was talking to him as he was walking back and when he got along side of the Dodge, the right torsion bar snapped and the car lurched and fell. He jumped when it happened.... Looked at me... Looked at the car... Looked back at me and said "I didn't do it!".
John