It's on the topic of glass explosions, but not pyrex. The bottom shelf of my refrigerator exploded while I was cleaning it. Luckily it's tempered glass, so there were no sharp shards. I had washed in times previous the same way. It's just a glass part that covers the crisper drawers. So I took it out of the fridge to clean it properly by putting it in warm, soapy dish water. I was slowly wiping it down and kind of bumped it against the sink side (like any other time I've washed it) when suddenly it exploded in my hands. I was very shocked and surprised. Glass was everywhere and even in the next room and hallway.
It was a mess to clean up which involved draining the water and vacuuming out the sink and floor. I had to put my hand down the drain in the other sink to scoop out glass pieces. It was not fun. So explosions can happen to tempered glass shelves as well. Luckily I found a replacement shelf that day at the Repair Clinic (awesome place). Ever since then I don't immerse the shelf in water. I carefully clean it with glass cleaner.