Northbound Highway 99 closed across First Avenue South bridge

All lanes of northbound Highway 99 are closed across the First Avenue South bridge in Seattle as crews make emergency repairs this weekend.

The closure began at 10 p.m. Friday and will last through 5 a.m. Monday, according to the Washington State Department of Transportation. The First Avenue South bridge trail also is closed for the weekend, with shuttle buses available at the south and north ends of the bridge to move cyclists and pedestrians around the work area.

Northbound traffic on Highway 509 and Highway 99 is directed to exit at South Cloverdale Street and follow a signed detour throughout the weekend closure, according to a news release from the agency.

Additionally, the following ramps closed Friday night and will likewise reopen Monday morning:

* First Avenue South onramp to northbound Highway 509;

* Occidental Avenue South onramp to northbound Highway 509;

* South Holden Street onramp to northbound Highway 99;

* Northbound Highway 99 offramp to South Michigan Street.

The repair work comes after an inspection in February revealed cracks in the steel grate decks of the bridge.

Copyright 2026 Tribune Content Agency. All Rights Reserved.

This story was originally published May 16, 2026 at 9:40 AM.