Air traffic controllers at the Salt Lake International Airport spotted smoke from a blaze Sunday night that had engulfed an abandoned school by the time firefighters arrived.

The abandoned school, at 749 S. Gladiola (2970 West), was reported burning at 8:53 p.m. and was left to burn for about an hour while firefighters watched to make sure the flames did not spread off the property, a dispatcher said.Fire investigators remained unsure of the cause of the fire Monday morning. Large amounts of rubbish inside helped fuel the blaze, the dispatcher said.