The crash happened about 5:08 a.m. on the freeway in the area of the 75th Street SE overpass, said trooper Mark Francis with the Washington State Patrol.
Witnesses at the scene said the man appeared to be trying to cross I-5. A driver in a Ford F-150 pickup truck saw the man and tried to swerve, Francis said.
The truck's passenger side mirror struck the man.
Another southbound car then struck the man, Francis said.
The man was taken to Harborview Medical Center in Seattle. Troopers were waiting on updated details from the hospital, Francis said.
The injured man was "very critical" but breathing, Francis said.
Troopers had not yet confirmed his age or hometown.
Traffic was backed up for about two hours, including surface streets in Everett as commuters sought alternate routes.
The investigation is ongoing.
View Crash, 3-26-13 in a larger map
More Local News Headlines
Everett teens were shot because one wore blue, police say Painter Elizabeth Webber leaves a legacy of faith, courage and art State attorneys are investigating Eyman's use of initiative money Panel gives green light to unfair labor practices case against Roe People who live along lakes can make a difference to protect them Family recognized for operating same small farm for 127 years 2 papal parades, more passes available after ticket outcry Front Porch: Mountlake Terrace storm cleanup
Our new comment system is not supported in IE 7. Please upgrade your browser here.