Officers and medics responded to the scene, in the 3800 block of Rainier Avenue South, at about 1:20 a.m. after receiving a report of a serious crash.
Arriving at the scene, they found that a white 2000 Nissan Altima had rolled over and crashed into a utility pole and fire hydrant.
The driver and passenger, both young women in their early 20s, sustained serious injuries. They were taken to Harborview Medical Center.
The driver told officers she was racing with another vehicle just prior to the crash.
There was a local power outage in the area while crews repaired the damaged utility pole.