*Updated at 11:06 p.m.

WICHITA FALLS (KFDX/KJTL) — Wichita Falls Fire investigators are working to learn what caused a fire at an abandoned school near downtown Saturday afternoon.

Several firefighters from the WFFD and Sheppard Air Force Base, along with police and game wardens, responded to the former “A.E. Holland School” just after 5:15 for a large structure fire on Jalonick Street.

WFFD fire investigator Jared Burchett said it started on the ground level, in a classroom and stairwell and moved upward to the roof, causing it to collapse. Fire Chief Donald Hughes said the building looks to be a total loss. He said they are investigating the possibility of vagrants inside the building.

20 fire units and 38 personnel responded. Crews will remain on-scene to overhaul the building. No injuries were reported.