this morning with the frightening scene overnight in Boston where more than 70 people at a concert had to be hospitalized. Officials citing chal and drug use. Reporter: This is serious. 22 people in... See More
this morning with the frightening scene overnight in Boston where more than 70 people at a concert had to be hospitalized. Officials citing chal and drug use. Reporter: This is serious. 22 people in the hospital. So many others had to be strapped to stretchers, yelling, in tears. The chaos playing out right in front of one of the world's superstar deejays. Overnight, a raging electric dance concert, turned into a nightmare. There's some people that are not doing too well in there. Reporter: With more than 70 concertgoers, mostly in their teens and 20s, falling suddenly ill during a packed concert, headlined by d.j.avicii. There was one kid, it took four cops to get him down. Reporter: 50 people treated on the scene. Officials citing alcohol, and Molly, and suspected in the deaths of two concertgoers just last weekend in Las Vegas. We saw some people on the wall. And emts were going to them and taking them out on stretchers. Reporter: Not just on stretchers. Strapped to them. Some screaming and flailing their arms. This is any parent's worst nightmare. This drug chemically cooks the brain over time. Reporter: Fortunately, none of the injuries were life-threatening. And officials at the garden could not be reached for comment. But overnight, D.J. Avicii, tweeting my thoughts go out to those affected and their families. And what's really incredible, is this comes after 800 people were treated at that Las Vegas concert. Have to keep that in mind. Thanks, gio.
This transcript has been automatically generated and may not be 100% accurate.