CHICAGO (CBS) — A teenager from north suburban Mundelein died Sunday night, after he was found unresponsive at Lollapalooza.

Police said a private ambulance took the boy to Northwestern Memorial Hospital around 7:50 p.m. Sunday, after he was found unresponsive inside the music festival at Grant Park.

A spokeswoman for the city’s Office of Emergency Management and Communications said Kitz-Miller was in critical condition “due to a medical emergency” when he was taken to the hospital.

Evan Kitz-Miller, 16, was later pronounced dead, according to police and the Cook County Medical Examiner’s office.

“Our thoughts and prayers are with his family and friends at this time,” OEMC spokeswoman Melissa Stratton stated in an email.

Lollapalooza organizers said they were saddened to learn of Kitz-Miller’s death.

“The individual’s family and loved ones are in our thoughts during this difficult time. We have no further information at this time,” spokeswoman Sandee Fenton stated in an email.

Police and OEMC officials said Kitz-Miller’s death is under investigation, and authorities are trying to determine if drugs were involved.

An autopsy was scheduled for Monday.

Through the first three days of the festival, at least 119 people at Lollapalooza were taken to hospitals. City officials have not yet