Meat Toothpaste forwarded me this thread from roadbikereview.com:
Last year I witnessed a spectacular carbon fiber steerer failure which I believe may have been caused by a too-heavy rider on an OCLV. The steerer abruptly snapped apart just above the fork crown, smashing the rider face-first into the pavement. He was seriously injured and had to be hauled away by the EMTs. I took photos . . .