Twenty-eight workers employed on a large, behind-schedule Toronto transportation project have tested positive for COVID-19, and dozens more are quarantined, possibly adding to construction delays.

Metrolinx, the transportation system operator that is building the 11.8-mile light-rail line extension along Eglinton Avenue, confirmed the positive tests. Another 70 employees of the public-private partnership consortium and constructor Crosslinx are quarantined.

The $3.14-billion project, originally scheduled to be completed last year, passed a milestone Jan. 13 with the wrap-up of major excavation for the Eglinton Station. Altogether, the line includes 15 below-grade stations and 10 above-grade stops.

The outbreak covered employees of Crosslinx and its subcontractors at eight locations along the rail line, according to tweets and blog posts by Anne Marie Aikins, Metrolinx senior media manager.

While tweeting that she hoped for “a full recovery for all Crosslinx workers,” Aikens added that “constructors are entrusted with a critical responsibility to run a safe site – this includes ensuring protections are in place (and followed) for their employees to minimize transmission of COVID-19.”

Metrolinx and Crosslinx have been fighting over the pandemic and its effects on project suppliers, subcontractors and staff throughout 2020.

Whether the outbreak, first reported by the Toronto Star, will worsen the already bad relationship is not clear.

Crosslinx is a general partnership that includes contractors ACS, Aecon, Ellis-Don and SNC-Lavalin. The parent entity of Metrolinx hired the companies under a public-private partnership agreement in 2015.

In October, Crosslinx filed a breach-of-contract lawsuit in Ontario’s Superior Court of Justice in Toronto against Metrolinx and its associated provincial agency, Infrastructure Ontario, accusing them of failing to comply with the P3 contract emergency provisions that entitle the consortium to a project “variation,” which means an extension or added payments. Crosslinx says the pandemic has added $106 million to its costs so far in delays from absenteeism, supply chain disruptions and new safety measures needed.

Metrolinx could not immediately provide a reply or comment to the accusations in the Crosslinx lawsuit.

As the pandemic unfolded and Toronto declared an emergency on March 23, the city allowed transit construction to continue as an essential service.

But Crosslinx says in its legal complaint that it ran into many problems. Suppliers and subcontractors informed it of potential delays in March and by mid-April, subcontractor absenteeism ran between 17% and 27%, the consortium complaint contends.

Metrolinx, in public statements, denied the claims soon after they were made and accused Crosslinx of using the pandemic as a cover story to obscure the consortium’s failure to keep up with the project schedule.

Metrolinx claimed Crosslinx “has consistently failed, month after month, for two years, to achieve their production rates," noting since 2018, only 72% of planned work has been completed.

A prior lawsuit between Metrolinx and Crosslinx, in 2018, was settled.