My high priestess and mentor Wow, I beg to differments. I don't see any problem with "died unexpectedly." It conveys useful information. If someone is languishing at the end of a lengthy illness, the death is not unexpected.

As for "untimely demise," while the guy was87, it still was an unexpected way to go. However, I don't like that expression either, Sparteye (what on earth is a "timely demise," except maybe in the aforementioned example?), and would use "unexpected death."