State Route 18 turned into a standstill on Wednesday after a collision between a semi-truck and a passenger car just east of Issaquah-Hobart Road left one person dead and shut down the highway in both directions for hours.
According to KOMO, emergency crews arrived around noon to a crash reported near milepost 22, while Eastside Fire & Rescue described it as a "rescue collision" near milepost 21. The Washington State Patrol later confirmed the only patient treated at the scene died, and the Washington State Department of Transportation reported the highway fully reopened around 4 p.m.
Traffic and detours
The closure backed up traffic onto local streets and stretched out drive times for afternoon commuters who tried to weave around the gridlock. The stretch of SR 18 between Issaquah-Hobart Road and I-90 has also seen intermittent planned closures recently as WSDOT finishes paving and interchange work tied to its I-90/SR 18 improvement project, according to WSDOT.
Why incidents on this stretch are disruptive
The Tiger Mountain corridor is narrow, with few good detour options, and it can seize up quickly when crashes or debris block the roadway, sending drivers spilling into the Snoqualmie Valley. Local reporting has documented similar traffic trouble in recent years, including a 2024 semi rollover near Issaquah and a March landslide that briefly shut down eastbound lanes, per FOX 13.
Washington State Patrol and local agencies are continuing to investigate Wednesday's crash. Officials have not released a cause and said no further details about other possible injuries were immediately available. This story will be updated as authorities share more information.
