The driver, 24, was seriously injured and was undergoing treatment Tuesday at an area hospital.
The Washington State Patrol has taken a blood sample for lab tests to determine if he was intoxicated or on drugs, Washington State Patrol Trooper Keith Leary said.
"Our intention is to book him into jail," Leary said. "I just don't know when that is going to be."
The man also is under investigation for felony hit and run involving another pedestrian, according to a State Patrol memo.
The dead man was identified as Darren Streeter, 47.
The fatal injuries happened behind a concrete barrier that separates cars from pedestrians along the trestle. The incident unfolded around 11:50 p.m. Monday, about three-quarters of a mile east of Everett.
The suspect was driving a Nissan passenger car when he rolled over a raised median on the onramp to the trestle, Leary said.
The car then drove over a raised dirt berm and around secured metal pylons before entering the pedestrian walkway, Leary said.
"This is the first time I have seen a vehicle drive on the pedestrian walkway area," Leary said. People use that walkway every day, he said.
Streeter was walking east with a friend he lived with on Ebey Island. Theresa Dubs, 55, was walking behind him and was clipped by the car's mirror. She was not seriously injured.
Streeter "was struck and thrown over the side of the trestle due to the impact with the car," Leary said. He fell about 40 feet.
"These people were doing everything correct and you would think they would be safe," he said. "You wouldn't think this would happen in 100 years."
The car kept going and struck a concrete wall where the walkway turns right toward Ebey Island at Homeacres Road, Leary said.
The driver suffered significant injuries to his legs and was taken by ambulance to Providence Regional Medical Center Everett.
The woman told troopers the couple ran out of gas in Everett and were walking home to Ebey Island.
The Everett Fire Department removed Streeter's body from under the trestle with the assistance of the Snohomish County Medical Examiner.
Eric Stevick: 425-339-3446, email@example.com.
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