There was a structure fire in the 100 block of 20th Street West Sunday afternoon.

The call came in around 2 p.m. and crews found a fire at the rear of the building possibly extending to the upper floor. Fire officials says the building was vacant at the time of the fire.

The fire was brought under control at 3 p.m. and the Fire Investigator has determined the cause of the fire was suspicious.  Damage is estimated at $30,000.  The investigation has been turned over to the Saskatoon Police Service Arson Investigator.