That link doesn't work. I haven't been able to see what the cause of death was.
Way back in the 70s I saw him (and Edgar) and others at a Detroit Fair Grounds concert. Sorry to hear it.
TIS
"Mankind must put an end to war before war puts an end to mankind. War will exist until that distant day when the conscientious objector enjoys the same reputation and prestige that the warrior does today." JFK