Fatal collision snarls traffic on NB I-5 through Everett

One person is dead after a fatal collision involving several cars in Everett on the westbound Highway 2 off-ramp to northbound I-5.

All lanes have cleared on I-5, but the backup stretches 7 miles.

Check the latest traffic conditions here.

Washington State Patrol Trooper Mark Francis says troopers first believed it was a hit and run because the scene spanned such a large distance. They now suspect the driver of the car that caused the collision suffered a medical emergency and died at the scene.

This is a developing story. Check back for updates.