Crack in the window. How should I proceed?

Hello,

I woke up to this crack on my window. It is inside, but I don't know how this happened. I usually open up the window completely to air out the room, so maybe it hit an object that was on the counter…

Anyways, I am unsure how to proceed. Should I contact my landlord first,, contact the Haftpflichtversicherung first (mine says it covers damages in rented rooms)?

Thank you