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SEATTLE, King County, Wash., Oct. 21, 2026 — Two people were hurt on Tuesday afternoon, October 20, when a three-vehicle crash involving a semi-truck blocked multiple lanes of northbound I-5 in Seattle. The collision occurred near the Michigan Street exit on the stretch of freeway near Boeing Field.
The Washington State Patrol said three cars and a semi-truck were involved. Trooper Rick Johnson reported that diesel fuel leaked from the truck onto the roadway and urged drivers to use caution passing through the area.
The Washington State Department of Transportation said the HOV lane and the two right lanes of northbound I-5 were shut down as crews worked the scene. One person suffered a broken arm, according to Trooper Johnson. It's not yet known whether other injuries were reported.
The Seattle Fire Department sent a hazmat crew after reports that the truck was leaking a significant amount of diesel. Emergency responders remained on scene as lanes were cleared.
No further details on the cause of the crash or the conditions of those hurt have been released. The investigation into what led to the collision remains ongoing.
We wish the injured a complete and speedy recovery.
Local Crash Information for Seattle, WA
The multi-vehicle crash was reported on I-5 in Seattle. For more crash news from the area, see our latest King County crash news.
Frequently Asked Questions
What are a truck's blind spots, and why do they matter?
Large trucks have wide blind spots along both sides, directly behind the trailer, and just in front of the cab. A car lingering in one of these zones may be invisible to the driver, which is why safety experts advise passing quickly and staying out of a truck's rear blind spot.
What is an underride crash?
An underride crash happens when a smaller vehicle slides partially or fully beneath a truck's trailer during a collision, often because the trailer sits higher off the ground than a car's crumple zones. These crashes can cause severe damage even at moderate speeds.
What commonly causes large-truck accidents?
Factors often cited in truck crashes include driver fatigue, following too closely, mechanical failure, cargo shifting, and difficulty maneuvering in tight traffic. Weather and road conditions can also play a role.
How can drivers share the road safely with trucks?
Give trucks extra following distance, avoid cutting in front of them, and pass on the left when possible. Because trucks take longer to stop, sudden lane changes near one can leave little time to react.
What to Do After a Multi-Vehicle Truck Crash in Seattle, WA
If you're involved in a crash on a busy freeway like I-5, try to move to a safe spot if your vehicle is drivable, and turn on hazard lights to warn oncoming traffic. Call 911 and wait for responders even if injuries seem minor, since adrenaline can mask pain from a broken bone or soft-tissue injury. If hazardous materials such as fuel are leaking, keep your distance and follow instructions from fire or hazmat crews. Get checked by a medical provider afterward and keep records of any treatment. Once you're safe, file a report with law enforcement and, if you're able, document the scene with photos, since those details can matter later for insurance or investigative purposes. Residents of Seattle dealing with the aftermath of a highway crash should also keep copies of any citations, tow records, or official crash reports for their files.
