Glass cracked above the cooker (Splash back)

Hello

I am a tenant and I have issue in the kitchen.
There is a crack on the glass (Located above the oven) and it is suddenly happened. I don’t know why that crack occurred. The crack started from the sockets plug corners. It is clearly that there is no sign of damage on the glass.

Can you explain to me in details why that crack occurred? As I need a good explanation in order to protect myself from landlord/agent blame.

Walls shift/sink/move (and generally have a mind of their own), and the fact that the crack radiates out from the socket, with no signs of negligence, is your saving grace.

Take photos, and nicely ask the landlord to get it repaired.
It's not for you to find someone to fix it, it is the landlords responsibility to make good.

The fact that it is above the cooker may come into it too. The heat will cause expansion in the glass and the general area around it, different substances expand to different degrees. If the fixings don't allow for some movement, cracks are likely on larger pieces.