Well this is what happens when you attempt to put a screw just a tiny bit to close to tempered glass.  I was in the midst of putting the shower door up, and was screwing this panel in.  I drilled a hole for a screw in the upper left hand corner, but it seems it was just a tiny bit to close to the glass, and when i put the screw in it shattered it.  If it had just been regular glass it would have probably just put a little chip in it, but it was tempered glass, so the entire panel instantly shattered, with no piece being bigger than 1/4″.   Hopefully it won’t be to hard (or expensive) to get a replacement.