Officers and medics responded to the scene, the Albert Lee appliance store in the 4200 block of 8th Avenue NW, at about 10:35 p.m. Tuesday after receiving a 911 call about the crash.
They found that the driver of a white car had somehow managed to drive backwards into the building, crashing through the front wall and windows before coming to a stop.
The driver was taken to the hospital with serious injuries.
A witness who works at a nearby brew pub told KOMO News that he heard a crash and looked outside.
The witness said it appeared the driver of the white car first drove forward and slammed into the witness' car, which was parked on the street nearby, then went into reverse and backed into the building several yards away.
Investigators are still trying to sort out exactly what happened.