That’s uncommon, but it does happen. Cooktops, oven doors, vanity sinks, and shower enclosures, etc. All have the chance of being bits of glass. It usually originates in a virtually invisible scratch that begins to release the energy bound in the glass during the tempering process. It seems to come put of nowhere though, when it shatters all at once and releases all that energy.

You either replace with glass, with it likely to never happen again. Or you do a shower curtain. Acrylic isn’t widely used for shower enclosures, and scratches and ages very poorly. Lexan would be a step up, but the cost for custom fabrication would be 10x glass. It doesn't last appreciably longer than standard acrylic. Research facilities usually replace it frequently when they are depending on it to resist pressure changes and be fully transparent.

Nothing in the way of any plastic or acrylic for shower doors. It is either a curtain or glass. As noted above it is rare but does happen.

Just get a new shower door.

I've never heard of this happening to anyone I know or ever read older posts where this happened to a forum member. I have heard of glass shower doors/panels being damaged during transportation or installation.

If you have swing in/out hinges, I wonder if someone swung the door a bit too hard into the shower head and caused a stress crack, which then caused the glass door to fail?

I have the same set-up in my two guest bathrooms and the only people that ever bang the glass door against the shower heads are my cleaning ladies!

I've seen this happen when glass and metal elements get tightened with battery operated screw drivers. They get over tightened and the stress over time is too much for the pieces assembled. Heck we see it when people used electric screw drivers to tighten switch plate covers. Sometimes assemblies require hand tightening.

I just looked at the instructions for installation and they emphasize that the door must be hung from perfectly plumb, level supports. If the structure is not plumb, that puts constant stress on the door. which could cause it to fail.

This has happened to us 3 times. Once in a shower - no one was home. Two other times in different exterior sliding glass doors. Glass people told us it does happen and probably due to an imperfection in the glass.

Yikes! I posted here some years ago when my glass vessel sink spontaneously exploded next to my head. Id been bent over changing the bag in the trash can in my powder room when it happened, and thankfully my hair was covering my face on that side when it exploded. I did have small, bloody scratches from it on my arms. Not because the glass was sharp, it was tempered THANK GOD! The scratches were because I was so close that the bits of tempered glass that shot out with great force were slightly imbedded into my skin. The injuries were very minor and healed up very quickly, but it was still a scary experience because it really sounded like a firearm had been discharged. There was a mess of tempered glass all the way to my front door (powder room was off of a large foyer) which was about 20 feet away. I’d been maybe 2 feet from it when it happened. Hubby contacted the company that manufactured the sink (and our local news station) and after being sent up the chain of command the company replaced our sink with one of their composite stone sinks as I was NOT going to have another glass sink. In our research we had discovered that it was most likely a manufacturing defect during the tempering process. I’ve had two glass oven doors shatter as well, but one was from the self cleaning cycle (which I refuse to ever use that function again though it happened decades ago) and once because the door got twisted weird when hubby was replacing some hinges, so neither of those were manufacturing flaws. We found some news stories of shower doors exploding (as well as other glass vessel sinks) after our sink exploded, so it does happen occasionally. That said, when we built our new home (finished 2 years ago now) we still went with glass shower doors in our primary bathroom. (But no more glass vessel sinks for us!)