(From Wikipedia)

Jean-Michel Basquiat,[4] though some sources list his death as heroin overdose only.[5]
John Belushi[4]
Ken Caminiti[6]
Chris Farley,[4] died of cocaine and morphine sulfate overdose.[7]
Zac Foley[8]
Lowell George[9]
Trevor Goddard[10]
Mitch Hedberg[11]
Sebastian Horsley[12]
Brent Mydland[13]
River Phoenix[14]
Eric Show[15]
Judee Sill[16]
Hillel Slovak[14]
Joey Stefano,[17] died of cocaine, morphine, heroin and ketamine overdose.
George V of the United Kingdom, his death was hastened by Lord Dawson of Penn using a speedball of morphine and cocaine.[18][19]
Layne Staley[20]
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.....

Woah, go back a minute. George V? ROCK 'N' ROLL, baby! Also, he was euthanised? I'm shocked by this but maybe at such stages this isn't frowned on in medical circles?