A semi-truck crash involving hazardous materials closed northbound State Route 509 at South 188th Street Wednesday morning, according to the Washington State Patrol.
The rollover happened near the Des Moines Way South interchange, just south of Normandy Park.
The Washington State Department of Transportation reported that the collision blocked the right lane and the on-ramp from South 188th Street, prompting a hazardous materials response.
Drivers were warned to expect significant delays in the area.
The crash will affect traffic heading toward SeaTac and Seattle-Tacoma International Airport.
No information was immediately available on injuries or the condition of the truck driver.
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