Damage spans from the ceiling to the floor and insulation covers at least two classrooms at Wisconsin Valley Lutheran High School in Mosinee.
"Now we're just more concerned about getting everything cleaned up," said Administrator Dave Berlinger.
School leaders said the damage is all a result of a massive water main break.
"Basically our carpeting is soaked and our drywall, ceiling tiles have fallen, insulation has fallen," said Berlinger.
Administrators said they're never seen anything like it and are still trying to figure out how much repairs will cost.
"This is the first time I've ever gone through anything like this, and our school has ever gone through something like this, so it's a learning experience for all of us," said Berlinger.
Kronenwetter Police officials said on Saturday night, they heard an alarm sounding at the school and were shocked at what they found.
"Water appeared to be leaking in through the ceilings of several classrooms, and in fact collapsed a couple of ceilings," said Lt. Terry McHugh.
Now, as school leaders start to clean up, experts are stepping in.
"It's affected a lot of building materials, our job is to get in there and dry those with minimal removal of those building materials," said RestoreU Restoration Services Owner Andy Radies.
With a lot of fallen insulation, wet desks, computers and textbooks, experts said the clean up won't be quick. The school will be closed for at least a week.
"This is a large area, there's going to be a lot of stuff happening in the next several days," said Radies.
Although that may be discouraging for some, administrators said they'll be just fine.
"This is where we put our trust in God," said Berlinger.
As they work together to overcome this unexpected obstacle.