I am writing to you with a very heavy heart. I want to sincerely apologize for the fact that the [item you borrowed, e.g., book, power tool, serving platter] you so kindly lent me was damaged while in my care.
The damage occurred yesterday while I was [describe the situation simply and honestly, e.g., using the drill in my workshop. I had it securely placed on the workbench, but when I turned around, my elbow accidentally knocked it onto the floor. The impact cracked the housing and the chuck is now jammed]. I feel absolutely terrible about it, as I know how much you value this item and I was being so careful.
I know that a simple apology cannot undo what happened, so I would like to make it right. I have found the exact model online, and I would like to purchase a brand new replacement for you. I have a screenshot of it and would be happy to order it for you immediately.
Alternatively, if you would prefer, I am more than willing to cover the full cost of a professional repair. Please let me know which option you would find most acceptable.
Again, I am deeply sorry for my carelessness and for betraying the trust you showed in lending me your property. You can reach me anytime at [Your Phone Number].
