The temporary repair system was completed in February following the sudden closure of the bridge in January (link opens in new tab). The first phase of the new cable-stayed bridge had only been open for about two months when bolts on one of the hold-down bearings under the side-span edge girder failed, allowing the girder to move upwards.

The ministry said that it has been working since January to discover the full story of what happened to the bridge. It has now received two lab reports as part of its investigations into the bolt failures but said that it is waiting until it has all the answers before discussing what happened.

Two independent labs - Surface Science Western (SSW) and Faculty of Engineering at Western University, and the National Research Council Canada (NRC) – have submitted reports but the ministry said that the study into the bolts is only one piece of the larger picture.

"The bolt study provided us with only a partial answer about the bridge, and as such we think it’s premature to discuss it on its own at this time,” it said. “The findings of these reviews are informing the ongoing work to determine what happened to the bridge. We feel it is important to present a full picture.” Once all the work is complete and the causes are known, the ministry will report back and make the information available, it said.