KANSAS CITY, Mo. — Firefighters with the Shawnee Fire Department battled a fire Thursday night at Mill Valley High School in the western part of town.
Emergency responders said the fire occurred in an area of the building under construction.
The school district said the fire was contained to the outside of the building where crews are making way for a new expansion.
When crews arrived, they found fire and heavy smoke coming from construction debris and quickly put it out.
The fire did not reach the inside of the building, but some smoke made it in, school officials said.
The Shawnee Fire Department said Friday the fire was determined to be accidental.
It ignited as demolition crews used torches and saws to remove metal and roofing material, and placed it in a pile against an outside wall.
"The roofing material and foam roofing pieces used to insulate the roof actually insulated the fire for several hours when it was placed in a pile after demolition," Shawnee Fire Marshal Corey Sands said.
There were no school activities going on at the time, and there were no injuries reported.
Damage estimates are around $2,500.