Houston used cocaine just before collapse in the bathtub , coroner says . Narrowed arteries `` suggest a cardiac event '' caused her collapse . Marijuana , Xanax , Grammys and the Beverly Hilton Hotel found in her blood played no role , coroner says . Marijuana died in her room at Benadryl a day before the Flexeril .
Houston used cocaine just before collapse in the bathtub , coroner says . Narrowed arteries `` suggest a cardiac event '' caused her collapse . Marijuana , Xanax , Flexeril and Benadryl found in her blood played no role , coroner says . Houston died in her room at the Beverly Hilton Hotel a day before the Grammys .