Waukesha North High School remains closed and will be until at least Aug. 19 after a fire broke out in its fieldhouse Aug. 1.
Five days after the fire started in the northwest corner of the fieldhouse, City of Waukesha Fire Department Marshal Brian Charlesworth said the investigation revealed the cause was related to the floor replacement activities taking place on the evening of July 31.
North High School is in the final stages of installing a new wood floor to replace its 20-year-old synthetic rubber surface.
"After a thorough investigation, the fire may have been started by the inappropriate storage and disposal of oily rags, which may have ultimately spontaneously combusted," Charlesworth said.
The plan was for the school to initially be shut down as a precautionary measure just for the weekend, but Principal Jody Landish said on Sunday the school will stay closed so the restoration team can do a thorough cleaning of the building.
And while it was labeled a "small" fire, Charlesworth said the damage will exceed several hundred thousand dollars. He added that it may take some time for an official estimate to be determined due to the amount of smoke damage that occurred throughout the building.
Since Monday, all operations for North have been taking place at Butler Middle School, 310 N. Hine Ave., which is about a mile to the east of North High School.
North's administrative assistants are working out of Butler Middle School and any meetings with administration, coaches, guidance counselors and staff will also be conducted out of Butler Middle School until at least Aug. 19.
The fire began in the early morning on Aug. 1. The Waukesha Dispatch Center received a call at about 4:50 a.m. from staff at the Linden Grove Nursing Home, 2330 Michigan Ave., reporting seeing strobe lights activated at Waukesha North High School, 2222 Michigan Ave.
Four department units quickly extinguished the fire. But there was still a large volume of smoke in the gym, some of the classrooms and hallways in the hours after the fire, Battalion Chief Steve Ore said.
The fire damage, however, was limited to the area of an exit door, Ore said.
"Basically the fire occurred where there is steel and it made a mess, but there's no structural damage," Superintendent Todd Gray said. "And it's not a main access or exit door."
Overall, Gray said he didn't believe the fire was a major setback in the completion of the new wood floor, expected to be finished in the next couple of weeks.
"There wasn't a lot of physical damage on the floor area," Gray said. "It's minor damage and is easily replaced. That's the really nice thing about gym floors that are wood."