Police say a woman was driving northbound on 23rd Avenue just after 4 p.m. when she crashed her blue Honda into a light pole near East Jefferson Street.
The driver wasn't injured, but two kids inside the car were. A 7-year-old girl was taken to nearby Harborview Medical Center with life-threatening injuries.
A second child was also taken to the hospital with non life-threatening injuries. Police say the second child was in a child safety seat.
Drug Recognition Expert officers responded to the scene to assist with the investigation, which remains on-going, according to police.
The northbound lanes of 23rd Avenue were completely shut down for hours while officers and detectives investigated.