[Scorpion]

This actually happens more than you might think.
Usually it's caused by penny pinching government not replacing the rails after a small collision just bends them. Unfortunately, those small bends and dings usually stress the joints. Then, even though the rail join overlap is in the direction of traffic flow, if the end is loose, and a vehicle hits just right, the already damaged rail collapses, and then the vehicle goes on to skewer itself on the next part of the railing, often with fatal consequences. :(

This is what happened to a friend of mine in the UK. Luckily for him, the engine got in the way of the rail, saving his life. The report on the accident slated the local 'council' for not maintaining the railings in that area. What should have been a glancing accident, with maybe a new fender and door, turned his car into a complete write-off :o