Mark Seliger, Courtesy Denim & Supply Ralph Lauren
06/26/2014 at 10:00 AM EDT
show in Boston transformed into a "Level 2 Mass Casualty" incident Wednesday night when more than 50 people required medical treatment for illnesses.
Thirty-six people were transported to Boston-area hospitals during the Swedish DJ's concert, primarily young people between the ages of 16 and 25, reports Rolling Stone
. Other young people treated at the scene were released – many to their parents.
The incident was declared a "Level 2 Mass Casualty," which notifies nearby hospitals "of the potential for 11-30 incoming patients and allow for them to be prepared for that influx," McKenzie Ridings, social media manager for Boston Public Health Commission, told the music magazine.
According to witnesses, people looked noticeably ill even before the concert began at the TD Garden arena. Inside, many felt overwhelmed during the show, which was not interrupted despite the illnesses.
"You couldn’t breathe if you were on the floor," concertgoer Mike Santostefano, 19, told The Boston Globe
. "It was the best and worst time ever."
Authorities said patients suffered mainly from drug and alcohol problems, according to the paper.
Most injuries are reportedly minor and it's unclear whether the club drug Molly
played a role in the illnesses.
"There may have been some illicit drug involved, but none have been identified," Michael Bosse, deputy superintendent for Boston EMS, told the Globe
Wednesday's show kicked off Avicii's summer tour in the eastern United States and Europe. After the show, the Swedish DJ – real name Tim Bergling – addressed the incident on Twitter
"Just hearing the awful news abt tonight. Its a terrible thing, I rly hope everyone is ok! My thoughts go to those affected & their families," he wrote.
This is not the first time Avicii, 24, has encountered a mass health issue at one of his shows. Last month, at least 29 people were sent to Toronto-area hospitals for illnesses related to drugs and alcohol following his show in the Canadian city, reports The Star
. Officials there told the paper that number is unusually high.