Officials are still trying to learn why an arson suspect set fire to an apartment complex, then attacked fire crews as they were trying to put it out.

Saturday afternoon,  Richland fire units responded to a blaze at 2555 Duportail, in the G complex, in the Shoreline Apartments.

Just before 4pm, firefighters tried to enter the affected apartment, where they found 21-year-old Nelson Aguayo.  He had set fire to a pile of clothes on the floor, then attacked fire fighters as they tried to put it out.   A total of four emergency crew members were assaulted.

Aguayo was eventually subdued and the fire extinguished.   Aguayo was apparently living there temporarily while working on a construction crew.   He's in the Benton County jail on a variety of obstruction and assault charges, but officials still don't know why he tried to set fire to the building.

The investigation continues.