Over at Scott Aaronson's blog his father has mentioned that, according to the coroner, he may have had undiagnosed type-I diabetes [1]. His father also mentions that Michael supported the charity givedirectly.org if anyone prefers to offer condolences that way.

It's a sad event for the theoretical CS community. I didn't know Michael, but looking at some of the other memorials some prominent researchers have written ([2], [3]), he appears to have been an extremely promising researcher and collaborator.

[1] https://www.scottaaronson.com/blog/?p=3468#comment-1746556

[2] https://blogs.princeton.edu/imabandit/2017/09/28/michael-b-c...

[3] https://lucatrevisan.wordpress.com/2017/09/26/3915/

Michael's father posted a comment to Scott Aaronson's blog where he confirmed it was not suicide or homicide, and speculated it might have been undiagnosed type 1 diabetes (among other contributing factors), but said they won't know for sure until the autopsy report is completed.

Preexisting congenital conditions. There is always one or two young people in any given year that decide to do some endurance event and simply drop dead from what looks like a heart attack.

I had two friends die of heart failure, one at age 15 and one at 25. Both healthy otherwise. One died after a soccer match, the other in his sleep one night.

Very sad news about Michael. My heart is with his family and friends.

dying from a disease is still a natural cause. Unnatural would be getting killed, suicide, accidents etc.

I don't mean to be coy (just trying to be respectful), but you should ask your doctor this. I actually did last year, after wondering what my risks were.