SEATTLE — Demolition of Seattle's Alaskan Way Viaduct started Friday, three days behind schedule after a series of snowstorms brought more than 20 inches of snow to the region.

Crews with the demolition contractor Kiewit Infrastructure West will remove the viaduct in three-span segments, which is about the length of a city block. The first section of the elevated roadway at the Columbia Street on-ramp at Columbia Street and First Avenue was removed by Monday. 

The Washington State Department of Transportation says it has had no formal complaints about noise but does acknowledge that demolition is not a quiet activity. 

Across from the Seattle Aquarium, large machines cut into the elevated road deck leading to the southbound lanes on the double-deck span.

The northern section of the viaduct that’s near the Battery Street Tunnel and the portion near Pike Place Market between Pike and Virginia Streets will also be part of the first demolition phase.

RELATED: Track demolition progress on interactive tracker

When crews begin demolishing the viaduct, they will systematically remove concrete pieces of the structure’s top deck first followed by the bottom deck.

Crews will remove portions of the viaduct in three-span segments, which is about the length of a city block. As crews remove the top deck of the viaduct, the rubble will fall to the lower deck and will then be trucked away. Workers can then remove the columns to the lower level and repeat the process for the lower deck.

A debris net will hang between the viaduct columns to keep debris from getting outside the work area. Crews will lay down bedding to protect the roadway and utility lines during construction.

RELATED: Crews demolish ramp to Seattle viaduct to prepare for future construction

Watch demolition on our viaduct cam, which updates every five minutes. App users, click here.

Quiet hours for demolition are before 7 a.m. and after 8 p.m. on weekdays. Saturday quiet hours are before 9 a.m. and after 8 p.m., and before 9 a.m. and after 5 p.m. on Sundays.

The entire demolition of the viaduct is expected to take about six months, but the Washington State Department of Transportation hopes to have the main portion of the viaduct down by June.

RELATED: Architect warned city against soon-to-be demolished Seattle viaduct

Scope of the Project, according to WSDOT

  • Shifting Alaskan Way to the west of the viaduct (completed in October 2018).
  • Removing the Alaskan Way Viaduct from South Dearborn Street to the Battery Street Tunnel.
  • Removing the Columbia and Seneca street ramps.
  • Building a new, temporary pedestrian bridge across Alaskan Way to Colman Dock.
  • Restoring the area where the viaduct once stood and then turning the space over to the City of Seattle's Waterfront Seattle Program.