A three-car crash involving a semi-truck shut down multiple lanes of northbound Interstate 5 near the South Michigan Street exit on Tuesday afternoon, after the truck began leaking diesel fuel onto the roadway near Boeing Field. Washington State Patrol Trooper Rick Johnson confirmed the crash was blocking multiple lanes and said it included an injury collision, with one person suffering a broken arm.
The Washington State Department of Transportation first logged the crash around 3 p.m. Tuesday, just south of South Michigan Street in Seattle, according to MyNorthwest. As reported by KIRO 7 News Seattle, WSDOT closed the HOV lane and two right lanes as crews worked to clear the scene, while Johnson advised drivers in the area to use caution.
Diesel leaking from the truck prompted a hazmat response from the Seattle Fire Department, which reported the deployment after receiving word that the semi was leaking a significant amount of fuel, the outlet's report noted. WSDOT confirmed emergency responders remained at the crash location as cleanup efforts got underway.
A Hazmat Response Built for Fuel Leaks
Under Seattle Fire Department operating guidelines, hazardous material incidents involving vehicle fuel leaks inside city limits trigger a specialized deployment made up of HazMat Unit 77, Decontamination Unit 1, a ladder company, an engine company, a medic unit, and a battalion chief, all tasked with stabilizing public safety threats. The protocol reflects the department's dedicated hazmat teams operating out of headquarters and Station 27.
Washington state law places the burden of cleanup squarely on the responsible party. Under RCW 90.56.020, the Washington Department of Ecology serves as the primary state authority for fuel spill abatement, requiring responsible parties to hire state-approved hazmat contractors and reimburse the state for its response costs. The Department of Ecology has noted that commercial vehicle wrecks resulting in diesel spills along highway shoulders are among the most frequent emergency calls its environmental response personnel receive, a routine hazard that also puts spill responders at heightened risk from surrounding traffic.
A Familiar Trouble Spot Near Boeing Field
Tuesday's crash landed in a stretch of northbound I-5 that has seen repeated trouble in recent days. Just four days earlier, on October 16, a separate multi-vehicle crash at the so-called Michigan Curve blocked four lanes near Boeing Field before crews could clear the roadway, per MyNorthwest's prior reporting. The curve has become a well-known choke point for northbound commuters navigating that section of south Seattle.
The corridor has also seen deadlier incidents. Hoodline reported that a semi-motorcycle crash killed a rider on northbound I-5 near South Albro Place, just north of the Michigan Street exit, on October 12, shutting down three lanes for several hours. Days later, on October 16, a three-car rollover near Mercer Street blocked multiple lanes and sent one person to the hospital after emergency crews evaluated three individuals.
Washington's Busiest Highway Under Strain
Interstate 5 through Seattle carries an average of 274,000 vehicles daily, making it Washington's busiest highway and the primary north-south spine connecting the Puget Sound region, according to WSDOT corridor data. Traffic volumes on the city's major freeway corridors, including I-5, had rebounded to 89% of pre-pandemic 2019 levels by 2023, per the Seattle Department of Transportation's 2024 Traffic Report, meaning lane closures like Tuesday's ripple quickly through peak commute periods.
The disruptions come against a backdrop of rising roadway danger statewide. Washington State Department of Transportation data shows traffic fatalities across the state's public roads reached 810 in 2023, a 75.3% increase compared to 2014, while serious injuries climbed to 3,413 that year. As of Tuesday afternoon, the total volume of diesel spilled, the exact cause of the multi-car pileup, and how long the lane closures delayed afternoon traffic all remained unclear.
