Half of an almost 100-year-old Toronto bridge was just torn down – but only half.

This partial demolition sounds a bit confusing on the surface, but it's just the prelude to a major expansion that will soon carry masses of passengers transiting the new East Harbour station serving GO Transit and thenew Ontario Line subway.

Metrolinx has released a timelapse video showing the careful demolition of the western half of the Eastern Avenue bridge, which has carried rail traffic over the street since its construction by the Canadian National Railway in 1926.

Work is underway to widen the Eastern Avenue bridge in#Torontowhich will help pave the way for the future#EastHarbourTransit Hub - a new interchange station and more service on the#LakeshoreEastline. Check out the progress Learn more:https://t.co/7dHaIfOoG4pic.twitter.com/W1OLm5oWJs

— GO Expansion (@GOExpansion)September 5, 2023

Almost a century later, crews demolished the bridge's western half as part of a phased teardown and expansion to support new tracks serving the planned East Harbour SmartTrack/GO and Ontario Line stations that will be constructed just south of the bridge.

Work starting in mid-July required overnight and weekend closures of Eastern Avenue between Logan Avenue and Broadview Avenue.

The phased demolition allows continued rail service over the eastern half of the bridge while crews rebuild the western half.

A new, wider rail bridge will be built over Eastern Ave in#TorontoTo do this safely, some road closures are needed. The improved bridge will pave the way for the future East Harbour Transit Hub and more service on the#LakeshoreEastLine. Read on:https://t.co/lCCJaJYeTKpic.twitter.com/H1xhs2go5m

— GO Expansion (@GOExpansion)July 18, 2023

This seamless process, maintaining GO train service at regular intervals through construction, is set to be repeated this fall with the demolition and reconstruction of the eastern side of the bridge.

Once all is said and done, the rebuilt and widened bridge will allow GO and the Ontario Line to operate through the same rail corridor, taking advantage of the underutilized right-of-way.

A new, wider bridge is being built over Eastern Ave in#Torontoto support construction of the East Harbour Transit Hub . This new station will provide connectivity to more#GOservices, future TTC Streetcars, and the Ontario Line. Learn more:https://t.co/l6fYmcUmHwpic.twitter.com/rWBQzcT3tU

— GO Expansion (@GOExpansion)August 15, 2023

Several bridges along the Ontario Line's route through this shared rail corridor will undergo similar widenings to accommodate the new15.6-kilometre, 15-station Ontario Linesubway that will connect Exhibition Place and the Ontario Science Centre (or at least the site it occupies today).