Spontaneous window shattering

Our TurnThePage friend is correct. It's in a locked, secured storage facility with another RV next to it protecting that window. No grass in sight and the parking lot doesn't get mowed, especially when it's snowing. ;) High, secure fence in a commercially zoned area. No signs whatsoever of how it could have happened. No point of impact. Instead, the window was bowed outwards (as though it exploded from pressure coming from the inside of the RV - crazy, I know - because, there's nothing airtight about an RV) and the force of the explosion popped a rivet right out of the frame, too. No prying, no scrapes, no signs of vandalism whatsoever. The black out window was the part that shattered. The second clear glass layer underneath remained intact, even after it fell right off the RV. So weird .... I see this happens to tempered glass and that it is generally a defect during the tempering process or during installation. Since only the black out glass broke, it would appear to be a tempering defect during the window making process. I googled the definition. Interesting reading and such a bizarre occurrence. Thank you, All!