Death of a beer glass

I keep, or rather, kept one of my Beer Glasses (8th Catford Beer Festival) at work to drink squash from. The glass was half full and sitting, minding it's own business, on my desk when the entire office heard the crack of glass.

I looked at the beer glass and it had cracked through the base and around the side but was still holding the liquid. After a while it began to 'weep' quash from the crack. I have never, ever had this happen to a glass before.