[Name, Company Name & Address here]
[Date]
Dear [name],
It was really disappointing to know that [person’s name] has passed away.
I offer my truthful condolences on his/her death. He/She was a nice person and I always respected him/her for his/her great qualities.
Please do not hesitate to call me for anything you may need my help for.
Sincerely,
[Your name]