The driver of one logging truck was transported to the hospital after logs from another truck went through their cab window on I-5 at SR 16.
The Tacoma Fire Department says the driver is in serious, but stable, condition.
The accident blocked lanes of northbound I-5 on Thursday, but the freeway reopened after 5 hours.
Washington State Patrol says the injured driver did not slow down properly and drove into the back of the other log truck.
Take an alternate route and expect delays if traveling in the area.