WSDOT said it would close SR 18 at 9PM, March 12, 2019 between Issaquah Hobart Road and the I-90 interchange near Snoqualmie in order to remove a semi truck and trailer from a ditch near the Tiger Mountain Summit.
The semi went off eastbound SR 18 around 2:30PM near the summit, landing on its side. Those lanes were completely blocked while WSP Troopers responded to the accident, causing back ups all the way to the I-90 interchange.
WSP said the accident was possibly the result of a load shift, but the exact cause was still under investigation. Trooper Rick Johnson reported the driver suffered a minor head injury. He did not know what the truck was hauling.
As an extended amount of time to is required remove the semi, all lanes were reopened around 3:45PM and a full nighttime closure – after peak commute hours – will be utilized to right the semi and tow it from SR 18. That closure is estimated to run from 9PM – 5AM.
Sara O’Hara, who was stuck in the back up and passed the accident scene, said it appeared the semi was heading downhill when it plunged off the roadway.
WSDOT also had to close SR 18 over Tiger Mountain Wednesday night (9PM to 6AM) to repair the guardrail destroyed by the semi.