A 15-year-old boy from Hawthorne, New Jersey broke both of his legs last week after he attempted to zip line across an athletic field using only a t-shirt. Jonathan Miller fell thirty feet from the line to the earth last Friday evening.

"His shirt got stuck and his friends said he would catch him, so he let go," Chris Mckeon, a witness, told CBS. "I told him that it wasn't safe, but his friends kept encouraging him."

The zip line, which was installed at Glen Rock High School, is supposedly inaccessible to the public during the summer, and is only used by seniors at the school. Miller climbed a tree, got on to the zip line platform, then wrapped a t-shit around the line and began to slide. As evidenced by the video below, it didn't go as planned.

It's unclear how the boy was able to access the zip line, and Superintendent Paula Valenti told CBS that "all security enhancements were in place." Still, the boy was able to get to the zip line and attempted to slide before his shirt became caught, prompting him to let go.

The boy, who broke his femur as well as bones in his feet, has yet to talk to police about the incident.