Dear Mr Harris,
I am writing to tell you about an accident that happened in the flat yesterday and to apologise for it.
While I was moving a wardrobe from the bedroom into the living room, I turned a corner a little too quickly, and one end of the wardrobe hit the window. The glass cracked across the lower corner of the pane. Fortunately, no one was hurt and the frame is not damaged, but I know that the window needs to be replaced. I should have asked a friend to help me, or hired professional movers, and I regret my carelessness.
I am very sorry for the damage, and I realise that it is an inconvenience for you. I have taken photographs of the window, which I can send you if you wish to see them.
Of course, I would like to pay for the repair. If you give me the name of a glazier you trust, I will arrange the work, or I can pay you the cost directly. Please let me know the quickest way to resolve this.
Yours sincerely,
Ivan Kozlov