Drivers will have to detour around a section of Richmond Street in the downtown on Tuesday.
Richmond Street between Oxford Street East and Piccadilly Street will be closed as of 7 a.m. for emergency watermain replacement.
The roadway isn't expected to be reopened until 7 p.m. A detour will be set-up to assist drivers in getting around the closure.
"Pedestrian access will be maintained around the construction area for the duration of this work, and businesses remain open," city officials said.
Several London transit routes will be affected by the closure. Riders are advised to check the LTC's detour page for more information.