WYOMING, Mich. (WOOD) — Godfrey-Lee Public Schools says an engineer determined corrosion caused by leaking water led to last month’s roof collapse at Lee Middle & High School.

The district released the structural engineer’s findings Thursday ahead of a community meeting about the investigation and the building’s future.

“It’s a serious issue,” Superintendent Kevin Polston said during a press conference after the meeting. “It would have been a catastrophe if the building was occupied during that time. There’s no question. We don’t take that lightly.”

Godfrey-Lee’s board members decided Monday that they will move forward with plans to demolish the entire wing and design a master plan for the site. The district says while doing so will take longer — an estimated 24-months — it will account for future education needs and improve accessibility for those with disabilities.

The district says the engineer found water caused a roof support to corrode and the roof separated from the exterior wall. The engineer said the failure happened at a bearing point of steel bar joists on the building’s west wall.

“The corrosion that happened on these bar joists, in the structural engineer’s opinion, happened over decades,” Polston said.

It’s unclear what caused the water leak and the district says the investigation determined its employees did appropriate checks and maintenance before the collapse. The district says there were no visible signs before the collapse to point to structural failure and therefore it was unpreventable.

“We have an aerial photo from April of 2018 that shows that wall was straight. There was no curvature, no deflection to show there was structural concern,” Polston said. “For the past two years, there has not been documentation of a maintenance request for a water leak or a call for a roofing repair.”

The good news: The structural engineer said other parts of the building built around the same time as the failed roof used different materials and a different design for structural support.

The district says it will carry out all the repairs recommended by building inspectors and the rest of the building will be ready for the first day of school on Aug. 19.

“We don’t have the final number but I think I can conservatively say that (repair costs are) a seven-figure number in any scenario,” Polston said.

So far, crews have removed the damaged portions of the building and debris and stabilized adjacent areas of the building. More demolition is planned before the repairs begin.

Godfrey-Lee says all asbestos in the area was sealed off and “did not present a health concern.” Testing continues in other areas.

The seven classrooms and 15 teachers normally located in the damaged part of the school will be moved to “unused or underutilized” space on the school campus, the district says.

Some parents told 24 hour News 8 they’re now questioning the integrity of the rest of the building and apprehensive about sending their students there in the fall.

“I know it’s an older school,” parent Jessica Hernandez said. “They should have really been more on top of it.”

Hernandez has a son who attends the school. She says she’s now considering other options for next school year.

“I’m really still debating if I want to consider bringing him to this school because of that matter,” she said.

Other parents say they believe the school has everything under control and the building will be safe for use on the first day of school.

“My son is just entering middle school this year so I just wanted to be sure that it wasn’t going to affect his year,” parent Laura Saldivar said. “I think it is safe but I know there’s many concerned parents out there.”

District officials plan to meet with architects and construction managers to further explore the wing rebuild and redesign, but won’t make a final plan until they get a formal response from the insurance company about what damage will be covered, which is expected in the next few days.

Godfrey-Lee says its insurance company previously told the district the damage would be covered, but the erosion of bearing blocks would be excluded because of “wear and tear.”

The school district says it wants to make clear that its top priority is the safe education of students.

“They (parents) trust us with their most prized position and we don’t take that lightly and we’ll honor that trust in us to make sure that the school that opens on Aug. 19 is safe,” the superintendent said.