The deaths of three young people attending a summer music festival in Fontana were caused by an overdose of MDMA, the San Bernardino County coroner confirmed Wednesday.
One of those who died was a 21-year-old woman from Chula Vista.
MDMA is the methylenedioxy derivative of methamphetamine and is also known as ecstasy or "E."
Alyssa Dominguez died after she was transported to the hospital from the HARD Summer Music Festival held July 30 and 31, approximately 50 miles east of Los Angeles.
Dominguez was a former student of Olympian High School and San Diego State University.
Derek Lee, 22, of San Francisco and Roxanne Ngo, 22, of Chino Hills, also died of an MDMA overdose, the coroner reported.
The three deaths were ruled accidental and are not related, the coroner's office said.
Local
Nearly 150,000 people attended HARD Summer this year, according to the San Bernardino County Sheriff's Department.
The Festival was moved from its 2015 location at the Los Angeles County Fairground in Pomona to a new spot after two college students -- including a Coronado High School graduate -- died of drug overdoses.
