WHITNEY Houston’s death was triggered by cocaine, a coroner’s report revealed yesterday.An autopsy on the singer, 48, found the cause of death was drowning due to heart disease and cocaine use.The Los Angeles coroner revealed the superstar singer, 48, took a line "immediately” before she drowned in a Beverly Hills hotel bathtub last month.Toxicology results indicated "chronic use” of cocaine over time had contributed to the heart disease. It is believed the Bodyguard star suffered a heart attack before slipping under the water and drowning.Relatives were said to be devastated at hearing cocaine was to blame.Whitney’s family said in a statement: "We are saddened to learn of the toxicology results, although we are glad to now have closure.”Coroner’s spokesman Craig Harvey confirmed Whitney appeared to have used cocaine "in the time period immediately prior to her collapse in the bathtub”.It said Whitney also had marijuana, Benadryl, Xanax and other medication in her system, but those drugs were not a factor.