GREAT FALLS - A deputy state fire marshall says a Sunday fire at the St. Paul's Mission School in Hays is being investigated as arson.
Fire Marshal Dick Swingley says he has ruled out all accidental causes for the fire.
It started in the library of the school on the Fort Belknap Indian Reservation.
No one was hurt, but the blaze gutted classrooms, the library, offices and the cafeteria.
Swingley has completed the physical investigation. He is working with the FBI and reservation police to determine who started the fire.
Reservation officials still haven't made a decision on where the school's 80 to 90 students will go to school this fall. St. Paul's served students attending kindergarten through sixth grade.