For building stairs, all the glass I use is tempered so all the cuts and holes have to be made before the tempering process. The drawback of tempering makes any edges the weakest portions of the glass (that includes any holes). In this style of guardrail, the glass is anchored in place through holes. In this case, one of the the holes wasn’t in line with the plane of the others and I tightened it too tightly. I installed it and moved on to the next piece and it wasn’t until 20 mins later that it all of a sudden just popped.BTW…how did the glass got shattered?