A California man attending a huge electronic music party in Las Vegas died Saturday morning after he was taken to a hospital.
The Clark County coroner's office identified the Electric Daisy Carnival attendee as 24-year-old Montomery Tsang of San Leandro.
His cause of death wasn't immediately announced.
Event producer Insomniac issued a statement saying it was "deeply saddened" by the death and hoped attendees would do their part to keep the weekend-long gathering safe.
Organizers estimate 134,000 people attended the opening night Friday.
Las Vegas police say of nearly 250 mostly minor medical calls the first night, only five resulted in trips to the hospital.
They also reported 29 drug-related felony arrests.
The event was criticized in Los Angeles in 2010 after a 15-year-old girl's fatal drug overdose.