Offer your sympathies over an accidental death in the family with this brief condolence letter.
Dear {Recipient},
I am so sorry to hear that {the deceased} died. I heard about the accident through {source} and I wanted to let you know that my thoughts are with your family. If you need any assistance in this terrible time, you need only ask.
{The deceased} was a great {relationship} and will be sorely missed. This accident is an absolute tragedy, and I am truly devastated by this news.
Love,
{Sender}