Why did the glass door suddenly burst?

What is the reason for the sudden burst of glass? 1. The glass has been loose for a long time. It may be that the nail that nailed the glass was too tight or too loose, and the owner accidentally touched it, causing the glass to break. The glass in the bathroom is exposed to hot air for a long time when taking a shower in the bathroom, so it will be broken if it expands with heat and contracts with cold for a long time. The sunshine is very strong in summer, if it is the cause of the hot cracking of the glass.