I had one come loose today on my Rad Runner 2.  Luckily I was on the train.  It goes to show you should check your forks before you ride. When I went to leave the train as normal this occurred. In my case one side of the tire came out  of the fork and was binding against the fender, so I could not move the bike with the front wheel down.  I hope this does not happen while I am riding.  I will be checking the tension of the clamp before I ride each time and make sure the wheel is seated properly. The clamp looks like it just came loose.  It was almost like someone loosened it on purpose. This was a little disconcerting to say the least.