Quoted from wayout440:
I've been putting glasses on my basement concrete floor for years and have never had a problem
I was at the PHOF one day playing Whitewater and my ball got stuck. Attendant came over and slid out the glass and started to set it down on the concrete floor. Attendant was super careful and slow about it and had it perfectly level to the floor. I started to put my hand up to say don’t do that!!! It literally exploded the second it touched the floor as I was opening my mouth. Glass EVERYWHERE. Whitewater was shut down now with glass all over the place under most every game in that aisle at the PHOF. So my point is you have been lucky. When they break it’s a true explosion and glass gets everywhere in your game. At least put a blanket or something soft down first.