Yosef, I'm so sad to hear about Mendel. Frankly, I cannot believe it.
Mendel was my Mesibos Shabbos counselor in Melbourne and later a head counselor in CGI there. Needless to say, he had an impact on my life.
I remember him giving us all cash prizes for saying Tehillim in shabbos mevorchim. It has always been one of the things I'm careful with since.
This hurts so much. I can't imagine what your family is going through.
If it helps, know that many are thinking about him too.