|The Young Nurses (L.A. Nurses; Nightingale; Young L.A. Nurses) (1973) [Doc Haskell]: Injected in the neck with an overdose of his designer drug when he falls onto his own needle during a struggle with Angela Gibbs.
The American Friend (Der Amerikanische Freund) (1977) [The American Mobster]: Run over by a train after being pushed in front of it. (I haven't seen this, but have read Samuel's account of it in his autobiography A Third Face.)
Golem, the Spirit of the Exile (Golem, l'esprit de l'exil) (1992) [Elimelek]: Dies (off-screen) of old age/natural causes, shortly before the story begins; his body is shown afterwards as Ophrah Shemesh attempts to revive him. (Again, I've only read Samuel's account in A Third Face.)
Somebody to Love (1994) [Sam Silverman]: Dies of old age/natural causes, while sitting on the curb after talking to Rosie Perez.