That's definitely nerve wracking! I had something similar happen, with a 5D series camera and my 24-70 f/2.8. It flew out of a bag and landed hard on the ground. The lens broke in the same manner that you described for your incident. Canon repair in Canada was able to fix it. The camera itself was fine. So now we both have more things to double check: Quick release levers on tripods, and closure locks on camera bags .