Semi rollover shuts down SR 509, triggers hazmat response Wednesday morning

A semi-truck rollover crash shut down all lanes from South 188th Street to the northbound lanes of SR 509 in SeaTac on September 10, 2025. The Washington State Department of Transportation reported the incident occurred on the right shoulder of the entry lanes to the new northbound SR 509 at milepost 24 near Des Moines Memorial Way S. Emergency crews responded at 9:00 a. m. to manage a hazardous materials spill, which prompted a swift response.

Officials did not provide immediate details about injuries or the hazardous cargo involved. By late afternoon, crews cleared the wreckage, allowing all lanes to reopen. WSDOT advised drivers to seek alternate routes while the closure was in effect. This incident highlights the risks associated with transporting hazardous materials on busy roadways. The response from emergency crews underscores the importance of rapid action in managing such hazardous situations.