LOUISVILLE, Ky. (WHAS11) – The Pleasure Ridge Park Fire Department says major structural flaws caused a gymnasium wall to collapse at Saint Andrew Academy over the weekend, sending three children to the hospital.

The school was hosting a mixer for local Catholic school children in grades 6 to 8.

LTC. Luke Goodman said witnesses reported that several boys were attempting to climb on the wall when it collapsed on a group of children. He estimated that a total of five children were treated for injuries, but two of them did not need to be transported.

Goodman said the concrete wall was “pretty much freestanding,” noting that it did not have any masonry ties securing it to the structure or its plywood backing.

Parishioners told investigators the wall had been there for years, Goodman said, with some suggesting it had been there since the gymnasium was built.

The fire department recommended the school close the gym after checking other walls that appeared similarly built.

“We’ve determined that until a full investigation is conducted by the church and the Archdiocese we can’t support the building being opened,” Goodman said, adding that the recommendation was given out of caution. “We are going to make the assumption that [the other walls] are not sound.”

A spokesperson for the Archdiocese of Louisville said engineers inspected the gymnasium on Monday. It will remain closed until all necessary repairs are made.

The three students transported to Norton Children’s Hospital are expected to recover. They are sixth graders that attend Saint Nicholas and Notre Dame Academies, according to the Archdiocese.