OTTAWA -- The city of Ottawa has chosen a Philadelphia-based firm to conduct an independent review of the broken-down light rail transit system.

The choice of TRA Inc., announced Monday, comes after the city scrapped its previous choice to conduct the review in light of questions about its independence.

TRA Inc. has never done work for the city, city manager Steve Kanellakos said in a memo. It also has no previous dealings with Rideau Transit Group—the city’s light rail contractor—or its parent companies.

The LRT has been down for more than two weeks after a Sept. 19 derailment, the system’s second in six weeks.

City officials say the line won’t return to service until the safety review is finished and the city accepts TRA’s recommendations.

Council and members of the transit commission will be provided with a work plan and anticipated timeline once TRA is on site.