Hate to say it, but my lens just cracked as well about an hour ago. I went to take the phone off my desk, and it kinda slipped from my fingers. The phone never made it completely off the desk. The two bottom corners were still touching, and the top half maybe a few cm off. Nothing I would ever consider a drop. When I flipped the phone around, to my surprise the lens was cracked. I don't know what to say? Any other phone I've owned in the past this wouldn't have happened to it in this very same situation.
HTC Droid DNA [ROM] Stock Jelly Bean [4.1.1]