I'm not sure how many have seen this before but I thought it was a pretty big eye opener, photos of a Canon EF 600mm f/4 (sometimes used by motorsport photographers) being retrieved from a crocodile infested swamp. Apparently, the guy was shooting from a bridge, with the 600 on a monopod with a 2x. The head snapped, with the lens hitting the concrete bridge, then rolling off, straight into the water!
Photos:
Tim Austin Images | Miscellaneous
Tim Austin Images | Miscellaneous