back in the mid to late 80's, my brother had a 73 or 74 dart sport [sunroof car-he hated that option. not sure why, it didn't leak].
he was going down a back street [35mph, possibly] and the passenger's side bar broke. just a "pop", and the car dropped. he thought he had a flat until he got out and looked.
a different [new to the car] bar and all was well with the world.
it was a break like Andy showed.
our area is a salt zone, so that's what we blamed it on.