Preble won't be ready by Sept. 2

Firefighters battle a fire at the Preble High School gym in Green Bay, Aug. 8, 2014. (WLUK)

GREEN BAY - As cleanup from Friday morning’s fire continues at Preble High School, the restoration company says the school will not reopen in time for September classes.

"We are looking at some alternative options cause we will have to make up the time that it's lost, instructional time, for the school year," said Natasha Rowell, Preble High School principal.

The Green Bay Metro Fire Department says the fire was caused by spontaneous combustion.

"(School employees) were cleaning the floors and resurfacing the floors on the gymnasium area. They placed rags that were used to clean up some of the product that was used to resurface the floor," said Lt. Nick Craig, Green Bay Metro Fire Department.

Officials say the rags were put in a plastic garbage can inside the gym.

"This fire was approximately three-quarters of a set of bleachers and took approximately 15,000 gallons of water to put out," Craig said.

School officials say an internal investigation into the fire is ongoing.

"I can guarantee you it wasn't done on purpose," said Mike Stangel, executive director of facilities for the Green Bay school district.

A crew of more than 100 people is cleaning up the damage.

"We don't know the totality of what we have to do," said J Murphy.

Murphy, with Paul Davis National, says the whole school will have to be cleaned because smoke and soot traveled throughout the building.

"It's really going to be a lot of odor control and a lot of just physical wiping of surfaces," Murphy said.

More than 2,000 students attend Preble but school officials are still discussing where the students will go.

"At this point in time we're still looking into some options and throwing some ideas around. Nothing's formalized at this point in time. We just want to do what is in the best interest of our students," Rowell said.

Murphy says crews will begin working throughout the night later this week.

In the meantime, Danz Avenue between the school and the football field will be closed so the restoration company can use the area.