Have experience moving glass. If you put the wrong pressure anywhere (particularly edges and corners, and it can be the glass' own weight as well that does it) it just insta-poofs into shards and dust. Though this is tempered/treated glass.

Was resting a shower door on my foot while a customer was getting her car ready and a corner happened to touch the concrete. I didnt even feel the glass touch the concrete. Boof, no more door.

Happens. But for anyone out there: you cant manhandle stuck tempered glass, because it wont flex and you can never tell where the forces are at (usually edges and corners, or otherwise hardware that concentrates forces) always deal with the tracks or hardware if you can. And have an extra person to distribute weight....glass is heavy furthering the risk.