Dozens of students were injured—at least one critically—when the stage dramatically collapsed during a show at an Indiana high school Thursday night.

The students were reportedly concluding a performance of the musical “American Pie,” when the stage gave way, sending about two dozen of them tumbling down into an orchestra pit.

“We have some seriously injured people,” a fire chief told The Indy Star. “Not one hospital is going to be able to handle this many patients.”

It’s still unclear how many were actually involved, but WTHR reports at least 16 students were hospitalized.

St. Vincent reported three patients at its Indianapolis location and ten at its Carmel hospital. Five patients who are 18 years old are in good condition; the conditions of eight patients under 18 are unknown (due to privacy regulations). Several of those at the Carmel location have “orthopedic-type” injuries. They are not expected to be life-threatening.

Two patients went to the Riverview Health Emergency Department on their own and are currently being evaluated for their injuries. IU North treated one patient, who has been released.

One student tweeted that he was released with a concussion.

Audience members told reporters they thought at first the collapse was part of the show, an assumption quickly refuted by the chilling screams that followed the students’ sudden drop.

“Nobody was expecting this. Everyone was seriously excited about it. It was a hyped up performance. It was good,” a student who was not expecting the stage to suddenly collapse told WTHR.

Police are reportedly investigating the scene.