Dear Niaz,
I hope you’re doing well. I wanted to talk to you about the [item you borrowed] I recently borrowed from you. Unfortunately, something happened while it was in my care, and it ended up getting damaged.
I’m really sorry about this. I know how valuable it is to you, and I feel awful that it happened while I was responsible for it. While I was [briefly explain what you were doing – e.g., carrying it, using it, transporting it], it [explain how the damage occurred – e.g., slipped, fell, got scratched, got wet]. It was completely accidental, but I understand that doesn’t change the fact that it’s now damaged.
Please let me make this right. I’d be happy to [offer a solution – e.g., pay for the repair, replace it with a new one, compensate you financially], whichever you prefer. Just let me know what would work best for you.
