The collision occurred about 6:45 a.m. underneath the 61st Avenue South overpass, and flames quickly engulfed on of the trailer trucks, sending a plume of black smoke high into the sky.

Firefighters rushed to the scene and were still trying to douse the flames more than 30 minutes later.

Washington State Patrol Trooper Cliff Pratt said the incident began when a small pickup truck cut into a lane of slow traffic and slammed into the back of a large truck.

Another trailer truck behind the pickup was unable to stop fast enough and slammed into the back of the pickup.

"That semi-truck driver had absolutely no where to go or anything to do at that point," Pratt said. "He slammed into the back this white pickup truck that cut in between the two."

The driver of the pickup truck, who's name has not been released, was killed.

A fourth vehicle crashed into the back of the rear trailer truck, but no one else was injured.

Northbound traffic on I-405 near the crash slowed to a crawl, and southbound traffic was backed up more than 3 miles at one point.

By 10:30 a.m., two southbound lanes were back open, but the right lane was expected to remain closed for several more hours.