It's hopefully well known that the old Atlas rockets (such as the one that John Glenn rode on) were basically big balloons. Let the fuel pressure out, and the thing would deflate. The rocket basically got it strength and rigidity from the pressure of the fuel inside.
I saw this video on The Space Review web site email I get every week and liked it since I've never seen it before. You know those really scary 15 foot tall snowmen that people buy at Lowes to haunt their front lawns during the holidays? If you let the air out of one of those you would get the same effect as this rocket deflating. It kind of flops over into it's own lap.
Although, this rocket seems to flop over like an overcooked piece of asparagus!
They didn't always explode in a huge ball of fire.