The 50-year-old Seattle man, whose name had not been released, was evaluated for driving under the influence before being taken from the accident scene to be booked into King County Jail, The Seattle Times reported.
The names of the victims had not been released.
The two fatalities were a man and woman who were pronounced dead at the scene of the 4:10 p.m. accident. A 25-year-old mother and her 2-week-old child were hospitalized, the newspaper said.
Notable deaths of 2014 [PHOTOS]