I’ve sold and installed shower doors for years. With tempered glass, any small hit on a corner or edge will do. My guys have had them explode while still wrapped from the factory and edge protected as they were carrying it.

I had a sliding door explode on me while trying to fix it. Not your FU, you just got caught holding the hot potato. Look in the corners of the other glass panel for a tempering logo. Then maybe talk to a local glass shop.

And, you have probably already learned this, please always wear shoes and safety glasses when dealing with glass.