This was from Drummerworld--
'Jeff Porcaro suffered a heart attack and died on August 5, 1992. He was using a pesticide in his yard and an allergic reaction to the substance triggered the attack. An autopsy revealed a serious heart condition that had been previously undiagnosed. A report issued by the office of the Los Angeles County Coroner a month later also mentioned that a minute trace of cocaine was found in his body. Although traces of cocaine can remain in a body for years, the media latched on to the drug reference and widely reported that cocaine abuse was the cause of death. Unfortunately this rumor persists, in spite of repeated statements by those who knew him well that he had not used the drug for many years.'