Torsion bars

[68PK21 440.6bbl]

I've seen them break like that.

 

[mr. fix it]

I had the same thing with a mid 70's Coronet wagon... parked the car and started to walk away then bam! the car went down like an injured warrior on one knee.
the driver's side had snapped just like what you show here.

 

[mr. fix it]

Thought I'd share these pics I just took of a Dart parts car that was sitting on the driver side snubber.I pulled the back of the bar out and saw the break pattern which was interesting.

View attachment 156476 View attachment 156478

This is a factory cast flaw... you can see the rusty area and the cleaner area with a distinct line.
Tells you how little it takes to keep a car suspended.