Halogen fixture problem or subterfuge?

I have a cheap halogen fixture above my workspace. 1 bulb in each end with a glass plate under the bulb and a wire cage around the glass. I came home to find 1 glass plate had burst and pieces were all over the floor. The light was originally supplied with 250 W bulbs. I have a 300 W bulb in the side that broke. (The bulb is still working fine.) I have had this arrangement in place for almost 10 years. My question is did one of my kids do something to the light or did it spontaneously burst? Neither kid is admitting to anything, but has anybody else had a glass plate shatter like this? Luckily it was like car glass and ended up with little squares all over the floor instead of dagger like shards.

well, it is tempered glass, to resist the stress of heat, soooo.......
a few things could have caused this.... if the lamp was on when it broke, water or something cold could have hit it causeing thermal stress fracture,.... over the life span of the light, the repeated heating and cooling Can occasionally cause glass to fracture, usually during warm up or cool down....
then there is the "random" factor.... kids, "MFO'd" (miscellaneous flying objects), and other freakish occurances can cause tempered glass to shatter.

It is not SUPPOSED to be on if I'm not there. It is in a deadend portion of my garage, so MFO's are unlikely- except if launched by little hands. The water theory? Perhaps, but again, a little person would have had to be present... Hmmm.

yes, little hands can be a serious factor.... for instance, one set of little hands once attempted to watch the Bologna DVD, lol