I found out today that my friends have lost their teenage son/stepson, who lived with them part-time. I don't know why he died. I only know that it was sudden and unexpected, and that he wasn't with my friends at the time. It's a massive shock - it's incomprehensible really, and apparently my friends are in denial and pretending that it hasn't happened.
He was a nice lad and kind to my family. I have several fond memories of him. I would like to write some of these in a condolence letter. As his parent and step-parent are understandably in shock and denial, would it be better if I waited a few days (or longer) before sending it? Also, I remember him as a happy and outgoing boy, and don't think he would have taken his own life, but as I don't know why he died, I'm worried about writing the wrong thing. Should I avoid mentioning how cheerful he was?
I've written condolence letters before, but never for someone so young or when the cause of death wasn't known. I'd be grateful for any advice.