Around 30 vehicles crashed in the westbound lanes of the 520 floating bridge during the evening commute on Monday. The westbound direction closed around 6 p.m. and reopened at 10 p.m.
The Washington State Patrol said conditions were slippery on the east high rise. The Washington State Department of Transportation was called into to bring deicing product to the roadway.
The dozens of vehicles that crashed were involved in several separate collisions.
The Seattle Fire Department and WSP troopers responded to the scene.
Trooper Rick Johnson tweeted there were no major injuries to report. He added that a Microsoft Connector bus, which is an employee shuttle service, stayed on the scene to help keep people warm.