Six construction workers performing concrete maintenance on the main span were killed in the collapse, which also blocked access to and from the Port of Baltimore, and severed a key interstate transportation route around the city.

The federal filing is part of a legal action brought in April by Grace Ocean and Synergy, which have denied that they or the vessel had any responsibility for hitting the Key Bridge. The two Singapore-based companies seek to limit their liability from the incident to no more than $43.6 million. The suit cites a 19th century maritime law that allows the shipowner to restrict the total amount of their liability to no more than the value of the vessel and its cargo, less salvage costs.

In response, the federal government says it is owed costs incurred by the U.S. Coast Guard, the Army Corps of Engineers and other agencies during the 10-week effort to clear wreckage and the Dali itself in order to re-open the deep draft channel. The effort also included the establishment of several temporary channels around the collapse site. Not covered by the claim are any post-collapse costs incurred by the state of Maryland, the City of Baltimore or the victims’ families. It also does not cover any costs associated with reconstructing the Key Bridge, an estimated four-year, $1.2-billion project scheduled to begin in 2025.

Although National Transportation Safety Board’s investigation has yet to determine an official cause of the incident, the agency’s preliminary report found that the Dali’s power outages were “mechanically distinct” from two that had occurred the previous day as crewmembers were performing routine engine maintenance in preparation for its voyage.

The federal filing alleges that rather than taking the necessary precautions to fully address previously reported heavy vibrations that were disrupting the Dali’s high-voltage system, Grace Ocean and Synergy Marine “jury-rigged” the vessel’s mechanical and electrical systems. It describes measures such as retrofitting a primary high-voltage step-down transformer with anti-vibration braces, “one of which had cracked over time, had been repaired with welds, and had cracked again.” Another “makeshift attempt to limit vibrations” is described as a metal cargo hook wedged between the transformer and a nearby steel beam.

Principal Deputy Associate Attorney General Benjamin C. Mizer said in a Justice Dept. statement that Grace Ocean and Synergy Marine’s actions were taken “out of negligence, mismanagement, and, at times, a desire to cut costs,” and that the Dali’s electrical and mechanical systems were configured “in a way that prevented those systems from being able to quickly restore propulsion and steering after a power outage.”

As a result, the federal lawsuit specifically asserts that the Dali’s propeller, rudder, anchor and bow thruster were unavailable “when they were needed to avert or even mitigate this disaster.”

A criminal investigation of the incident also was launched in April by the Federal Bureau of Investigation. No charges have been filed against the companies or crew members, most of whom have been allowed to return to their homes in India and Sri Lanka.