A driver plowed into a crowd of protesters in the early hours of Fourth of July, critically injuring two women, one of whom died later in hospital, according to authorities.
Dawit Kelete, 27, of Seattle, drove a white Jaguar around vehicles that were blocking the closed Interstate 5 in Seattle and barrelled into the panicked crowd at about 1.40am, according to a police report.
Video from the scene showed people shouting “Car! Car!” before fleeing the freeway.
Summer Taylor, 24, of Seattle, and Diaz Love, 32, of Bellingham, were taken in critical condition and with multiple injuries to Harborview Medical Center, according to a spokesperson.
Ms Taylor died on Saturday evening. Ms Love remains in serious condition.
Ms Love had been filming the protest for almost two hours on a Facebook livestream captioned “Black Femme March takes I-5” when the video ended abruptly. With about 15 seconds left, shouts of “Car!” can be heard as the camera starts to shake before screeching tyres and the sound of impact are heard.
Video on social media showed the car striking two people. Police released pictures of the driver's car, showing significant damage to the bumper and windshield.
The driver was in custody, Washington State Patrol Captain Ron Mead said.
Kelete was booked into the King County Correctional Facility on Saturday morning on two counts of vehicular assault and was denied bail.
Officials are trying to determine the motive as well as point of entry onto the interstate.
Captain Mead said Kelete was suspected to have driven the wrong way on a ramp. Troopers did not know whether it was a targeted attack, but impairment was not considered a factor.
Seattle has been the site of prolonged unrest following the police killing of George Floyd in Minneapolis in May, which has led to protests across the country. Dozens of people were arrested over the past week in connection with protests, as demonstrations continue after authorities cleared the “Capitol Hill Occupied Protest” zone on Wednesday.
Protesters had shut down the interstate for 19 days in a row, police said. Captain Mead said that the freeway is “simply not a safe place” for pedestrians, and said he hoped protesters would cease what he termed “unlawful behaviour” in blocking the interstate.
“My hope is, as a result of this tragedy, protesters will reconsider their desire to be on the interstate because I cannot guarantee their safety, plain and simple,” the police chief said.
Protesters were on the freeway for more than an hour before the car drove around the blockade around 1.36 a.m.
Seattle police said the southbound lanes of the freeway remained closed for investigation.
Associated Press contributed to this report