Photo by Alex Wessely

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Update (1:30 a.m. EST): Boston EMS deputy superintendent Michael Bosse reports that around 50 people were treated at TD Garden, while an additional 36 other patients were transported to medical centers for treatment.

Avicii's tour stop in Boston on Wednesday night didn't end well, with at least 38 attendees being hospitalized after the show.

The Boston Globe reports that many of those hospitalized had consumed "a dangerous substance," according to an EMS worker involved in the treatment of some of the patients.

According to ABC affiliate WCVB, as many as 65 people were taken to the hospital due to dehydration from alcohol and drug usage, citing officials at the venue TD Garden.

Massachusetts General Hospital said most of the patients brought in were between the ages of 12 and 19. At press time, none of those treated were said to have life-threatening issues.

NBC affiliate WHDH has estimated that up to 80 people were treated for medical issues, although only about half of them were transported to local medical centers.

Just last month, at least 29 people were hospitalized for similar drug-related issues following an Avicii concert in Toronto.