Tarps drape the Westside Road overpass as crews work on the retaining wall which collapsed late last year.

Provincial officials have determined the failure of two retaining walls at the Westside Road interchange last year was indeed a unique event.
On Nov. 20, the panels of the west abutment retaining wall at the Highway 97/Westside Road interchange collapsed onto the roadway, prompting an immediate closure to traffic.
Engineers discovered the retaining wall on the east abutment was also shifting so steel supports were installed on both sides and traffic returned to the highway after rush-hour chaos for several days.
The province engaged Buckland and Taylor Ltd., a bridge engineering firm, to investigate the cause while repairs began.
"Their testing of materials from the site has determined embrittlement at the bends in certain steel reinforcement bars connecting the concrete facing panels was a contributing factor in the collapse," said ministry spokeswoman Kate Trotter on Wednesday.
The steel reinforcement bars, which look like small ladders, extend horizontally into the fill at the ends of the overpass.
"The thorough investigation into the failure is continuing, and includes detailed geotechnical analysis, further materials testing, analysis of soil settlement, mapping of the failure areas and analysis of findings from taking apart the opposite wall to learn about other factors that may have contributed to the collapse," said Trotter.
Ministry of Transportation officials initially thought repairs would be completed this month, but now it will be mid-March. Work will begin this week on the final phase, said Trotter.
"The first phase of repair works at both the west and east abutments is complete, and involved the preparation of a mounting surface for the finishing panels. Work included removing all the panels under the abutments on both walls, preparing soil and placing shotcrete on the exposed face of the soil to prevent weathering.
"Ledcor, the contractor for the Westside Road interchange project, is starting the process to attach the finishing panels."
The retrofitting of the panels is a complex process, Trotter explained.
"As such, to design a repair that ensures quality and durability required more time than anticipated. Current traffic patterns will remain in place until further notice.
"The ministry will continue to ensure that any traffic pattern changes take into consideration hockey games and other community events."