OTTAWA -- Transport Canada has for more than a year expressed concerns over maintenance and repairs on the Ambassador Bridge with the Canadian Transit Company, the private company that owns the cross-border suspension bridge between Windsor and Detroit -- the busiest border crossing in the country. Here's a timeline of recent events:
June 2014: An engineering firm that inspected the bridge recommends that the Canadian side of the crossing be completely rehabilitated or replaced.
September: Transport Canada officials inspect the bridge and agree there is a need to repair or replace the Canadian approach.
June 2015: Transport Canada officials again inspect the bridge and ask the Canadian Transit Company for immediate repairs on the sidewalk, bridge railings and concrete deck.
July: The company provides Transport Canada with a short-term plan to complete localized repairs to the concrete deck on the Canadian approach, remove the sidewalk entirely and replace the barrier wall with a new, pre-cast barrier wall. The company promises to start work by September. Transport Canada deems the plan acceptable, but "did not consider the long-term risks of the Canadian approach concrete deck to have been mitigated," officials told Transport Minister Marc Garneau late last year.
Sept. 21: Transport Canada asks the company for more engineering reports about the state of the concrete deck, its estimated lifespan and its ability to support the traffic load.
Oct. 2: The company responds, but transport officials "remain unsatisfied" and follow up with the company.
Oct. 9: The company provides an update on mitigation measures and repairs. In briefing material to Garneau, officials write they remained concerned that "key risks have not been mitigated and that engineering evidence regarding the structural integrity of the Canadian approach concrete deck has not been provided." The City of Windsor closes Wyandotte Street, which crosses underneath the bridge after reports of falling concrete.
Oct. 14: Windsor closes two more streets, amid continued reports of falling concrete and public concerns about vehicle safety.
Oct. 15: A Transport Canada inspector meets the bridge company and municipal officials. The city is unable to provide evidence of fallen concrete. The inspector tells the company about the department's ongoing concerns about repairs and discusses "the company's unfulfilled commitments to complete repair work."
Oct. 16: The company tells Transport Canada it will install a wooden structure underneath the bridge to catch any concrete that could land on city roads. The company also promises to replace the barrier wall on the bridge within two weeks and, weather permitting, continue work on the bridge through the winter. The company also promises to do a full engineering inspection starting Oct. 26. The inspection is scheduled to take two weeks.
Oct. 26: Municipal officials reopen the streets closed for safety reasons.
August 2016: A Transport Canada inspector walks the Canadian side of the bridge and raises concerns with senior department officials about work on the sidewalk and railings.
Sept. 3: Transport Canada orders the company to place temporary concrete barriers along the bridge because the current curbs and railing "would not deflect traffic back onto the bridge" should a vehicle strike the side of the bridge.