Albert Hofmann, the chemist who synthesized lysergic acid diethylamide (LSD) in 1938 died of a heart attack on April 29, 2008 at the age of 102. Hofmann (Wikipedia entry) also discovered the hallucinogenic properties of LSD because of an accidental ingestion about five years after he first synthesized the compound. The impact of this train of events on our understanding of the neurochemical function of the brain stretches across many disciplines from basic neuroscience to studies of consciousness and theology.
Obituaries: NYT, LA Times, Reuters.
[and thanks to reader Neuro-conservative who already noted this for the DM readers]