The crash took place around 9:45 p.m. at 2nd Street and 4th Avenue, when a speeding SUV hit a car carrying two women.
After the crash, investigators say the driver of the SUV - Joshua Steiger - jumped out of his car and took off running.
Witnesses spotted Steiger at a nearby Fred Meyer on River Road and called police. Officers used K9 units and the Pierce County Sheriff's boat to search the Puyallup River, but did not locate their suspect.
The 22-year-old driver of the hit car was trapped for 30 minutes while fire crews used the Jaws of Life to free her from the vehicle.
The woman was rushed to the hospital with critical injuries, and her 22-year-old passenger had serious injuries.
Steiger was arrested for vehicular assault on Sunday morning. He will be booked in Pierce County Jail.