Seven weeks after the collapse of the Francis Scott Key Bridge in Baltimore, leaders of federal agencies responding to the disaster told Congress on Wednesday that the country needs to take steps to address the risks large ships pose to the country’s essential infrastructure.

Vice Adm. Peter Gautier, deputy commandant for operations of the U.S. Coast Guard, said that even as investigations continue, it is already clear that because of how much “the size and complexity of ships has grown over the years,” regulatory systems may not have kept pace “with the increased risks these vessels pose.”

A national board of inquiry is being convened to assess the risk-management tools to keep port operations safe, Gautier said, with the goal of developing a holistic, national approach “to reduce the risk of major incidents.”

Gautier testified before the House Committee on Transportation and Infrastructure alongside Maj. Gen. William “Butch” H. Graham of the U.S. Army Corps of Engineers; Shailen Bhatt of the Federal Highway Administration; and Jennifer Homendy, chair of the National Transportation Safety Board.

The questioning, growing heated at times as lawmakers grilled the four officials about investigations into the accident and funding sources for rebuilding, came a day after the NTSB released its first report on the March 26 tragedy - outlining the agency’s initial findings from its investigation into the cause of the crash that killed six people and crippled the local economy by cutting off access to Baltimore’s port.

Investigators wrote in the report, published Tuesday afternoon, that the Dali - the Singapore-flagged cargo ship that destroyed the bridge - suffered repeated electrical failures before the crash. The vessel had two electrical blackouts while docked in the Port of Baltimore 10 hours before setting sail, then had two more blackouts that disabled critical equipment in the moments before hitting the bridge.

The agency did not indicate whether its investigators thought crew members or the ship’s owners had done anything wrong that led to the bridge strike and said the ongoing inquiry will examine whether the first blackouts in port had anything to do with those that occurred just before the Dali took down the bridge.

Homendy told lawmakers at the hearing that NTSB investigators are concentrating on what happened with the electrical systems before the crash and are trying to “replicate some of the electrical problems that were seen that day.” Investigators, working with the system manufacturer, Hyundai, are examining and testing various components, she said.

A mistake by a crew member working on part of a diesel engine caused the initial in-port blackout, the investigation found, and a second blackout in port was related to insufficient fuel pressure.

The Dali then left port and set sail on the Patapsco River, experiencing another blackout about half a mile from the Key Bridge. That power outage stopped the vessel’s steering pumps, according to the investigation, leaving the rudder immovable. NTSB experts are still investigating when an emergency generator started up, which would have been able to power an emergency steering pump, allowing the rudder to move again.

Even with emergency power after the blackouts, Homendy said Wednesday, the rudder was less effective for steering because the generator powered the radio communications and the ship’s lights - but not the propeller.

“They were essentially drifting,” she said.

The investigation is sprawling and complex, she told lawmakers, and the NTSB team has been on the scene of the Dali crash in Baltimore since the Key Bridge collapsed seven weeks ago - an unusually long time for on-scene fact-finding. “It is unprecedented, to be on board that long,” she said.

Bhatt also emphasized the immensity of the effort. “I have never seen anything at this scale,” he said. “It is a monumental task to clean up this site and rebuild.”

The Coast Guard is responsible for overseeing the safety of U.S. waterways and risks related to shipping. But questions have been raised, including on Wednesday, about whether it has acted aggressively enough.

The move to launch a nationwide board of inquiry is an indication that the country has not been fully prepared for all the changes - and dangers - ever-larger container ships have brought to U.S. waterways.

“It’s time for us to more broadly understand these risks,” Gautier said.

The inquiry - spurred by the Dali crash - will “assess the efficacy of the Coast Guard’s suite of risk management tools, evaluate how recently they’ve been used within major ports, and establish a holistic, national-level approach to develop risk profiles, identify ways to address vulnerabilities and propose actions to reduce the risk of major incidents,” Gautier said.

Homendy noted that back in 1988, her agency had pushed for the Coast Guard and federal highways officials to evaluate the adequacy of pier protections on bridges over navigable waterways in U.S. ports and harbors. But according to Homendy, the Coast Guard said at the time it did not have the authority to take action.

Gautier noted that an overall risk assessment was performed in the Port of Baltimore – but that was more than 20 years ago.

The Coast Guard meets with stakeholders at ports around the country “to evaluate the totality of the risk” when things change, such as when a channel becomes deeper or a new bridge gets built, Gautier said. The new national inquiry will look at how the

Coast Guard conducts these assessments and “how recent they are in the ports around the country,” he said. It will also examine the 10 biggest ports for lessons that have been learned on bridge protection systems, hazards to navigation and other factors “so we can draw some conclusions and then move out with a refined toolkit to other ports around the country,” Gautier said.

Homendy said that while she is “very encouraged” by the Coast Guard’s new inquiry, she is urging states to conduct expedient risk assessments of their own and and not wait for the full NTSB investigation or for new nationwide recommendations.

“This could happen in any of your districts,” she told the members of Congress.

The Key Bridge was ordered closed swiftly after authorities received a warning call from the ship, Homendy noted, but she said other bridge structures have advanced warning systems that Baltimore did not, something the NTSB is examining as part of its investigation.

Homendy and Gautier said they did not know whether the Dali collision could have been avoided if the vessel had been guided by a tug boat at the time of the blackouts. Homendy said NTSB investigators are also looking into that question.

The FBI has launched its own criminal investigation into the Dali, including whether the crew knew of serious system problems before setting out in the early morning darkness on March 26. Dozens of law enforcement officials boarded the Dali on April 15 to search for evidence.

Attorneys representing the city of Baltimore and a local business executive have filed separate complaints in federal court in Maryland against the Dali’s owner and manager, alleging negligence before the crash.

In court, the Dali’s owner, Grace Ocean Private Ltd., and its manager, Synergy Marine Pte Ltd., both based in Singapore, have asked a federal judge to limit their liability in the tragedy to about $43.6 million.

Rep. Sam Graves (R-Mo.), chair of the transportation committee, indicated that some Republicans are not in a hurry to pass legislation ensuring that the federal government fully reimburse Maryland for the cost of rebuilding the bridge. He noted that actions by the Federal Highway Administration so far mean Maryland will have 90 percent of costs recovered over roughly the next six months.

Graves said an early estimate put the price tag for replacing the bridge at $1.2 billion, but later estimates came in at between $1.7 billion and $1.9 billion.

“It’s important we have a very firm estimate before we take any further action on the cost sharing,” Graves said.

Federal and Maryland state officials are eager for Congress to move quickly to commit to the full reimbursement.

The Dali, which was trapped under part of the bridge until Monday, is expected to be moved back to shore in Baltimore early next week. So far, more than 6,000 tons of steel and concrete have been removed from the collapse site, Gautier said, and limited access to the port has been restored.