Construction on Toronto's upcoming Lower Don Bridge has officially begun, which will eventually carry the under-construction Ontario Line over the Don River between Corktown and Riverside. 

To prepare the site for the start of construction, Metrolinx crews cleared the area, relocated a watermain that went beneath the railway, and shifted the train tracks throughout 2023. 

🌉A new bridge for Toronto 🤩
Construction has now started on the Lower Don Bridge, which will carry the Ontario Line over the Don River between Corktown and Riverside. Learn more: https://t.co/qs71WixmMk pic.twitter.com/CIGTYOU1mV

— Ontario Line (@OntarioLine) May 2, 2024

The tracks had to be shifted to make it possible for continued GO service during the Ontario Line construction since the future subway line will run alongside GO Trains in the shared rail corridor in the area. 

Construction on the bridge's east support structure is starting with the installation of two concrete and steel piers that will support the foundation of the bridge. 

Once the east support structure is completed, Metrolinx will move onto the west side. The forthcoming bridge will be built north of the existing Lower Don Bridge over the Don Valley Parkway and the Don River. 

The Ontario Line is set to bring 15 new stations to Toronto along a 15.6-kilometre subway line running from Exhibition Place, through the downtown core, up to the Ontario Science Centre. 

Construction for the rapid transit line is expected to be completed by 2031.