Dozens of University of Wisconsin-Madison students plunged into a lake near campus when a pier collapsed beneath them, according to officials and dramatic footage.

The Memorial Union Terrace pier at Lake Mendota folded into the lake, sending an estimated 60 to 80 students into the water on Labor Day Monday afternoon, UW-Madison police said, according to the Milwaukee Journal Sentinel.

Video of the moment shows the pier collapse in one spot before other parts also fall like a line of dominoes.

“I turned to this one girl, and we were like, ‘Oh my God. Did that really just happen?’” student Gabrielle Willbrandt told WMTV. The freshman was one of the many standing on the pier when it went down.

At least 25 people suffered minor injuries, though only one person was taken to the hospital, police said, according to the Journal Sentinel.

Five people were treated at the scene, while the others didn’t need any treatment.

The pier was supposed to be removed for the season Tuesday, authorities said.

“Me and my friend who I was swimming with heard a big noise, and the whole dock was collapsing,” student Nicole Mitchell told WISC.

“There were dozens and dozens of students on it, just tanning or jumping into the lake or talking with their friends and suddenly the whole thing gave way.”

Students swam back to shore while holding their phones out of the water, Mitchell said.

An investigation into the collapse is underway.