A Seattle police officer was killed early Sunday while attempting to assist during a three-car collision on an interstate, authorities reported.

The officer, who was not immediately identified in accordance with his family’s wishes, was outside his vehicle assisting with a three-car collision when he was fatally struck by an additional motorist, according to a readout from the Seattle Police Department. The officer had just gotten off of his shift and was trying to render aid when he was struck, Assistant Chief Tom Mahaffey said during a press conference on Sunday.