Federal officials agreed Friday to inspect the Maine tracks of the Montreal, Maine and Atlantic Railway, less than one week after a runaway train operating on the company’s tracks derailed and sparked an explosion that killed dozens in a Quebec tourist town.

Officials with the Federal Railroad Administration notified members of Maine’s congressional delegation Friday that they will inspect MMA’s tracks in the state next week, according to delegation staffers.

Maine Reps. Mike Michaud and Chellie Pingree had requested the inspection in a letter sent Thursday to federal transportation officials as the Canadian investigation continued into the disaster which is believed to have killed at least 50 people in Lac-Megantic, Quebec.

Preliminary reports have suggested that the accident may have been caused when brakes failed to hold the parked train, sending it several miles downhill into the lakeside town. But Maine officials have expressed concerns about the condition of MMA’s tracks in the state.

“An event like this requires a full accounting of the vulnerabilities of existing rail infrastructure in Maine,” Pingree and Michaud wrote in their letter to the heads of the Federal Railroad Administration, the National Transportation Safety Board and the U.S. Department of Transportation’s Pipeline and Hazardous Materials Safety Administration.

“We all have an obligation to ensure that any safety issues are identified and dealt with quickly. This is even more important at a time when crude oil shipments through Maine are skyrocketing,” they wrote.

Maine Sen. Susan Collins, meanwhile, said she raised concerns Thursday about the adequacy of the tank cars involved in the Lac-Megantic incident during a conversation with NTSB Chairwoman Deborah Hersman. Those cars could become one of the major policy discussions in Washington in response to the incident just across Maine’s border.

But nearly a week after Canada’s largest rail disaster in more than a century, many lawmakers on Capitol Hill and Obama administration officials are taking a more cautious, wait-and-see approach to an issue with potentially significant economic and safety implications on this side of the border.

“I plan to work closely with investigators to uncover the accident’s cause and work to find ways to prevent this kind of disaster in the future,” said Rep. Jeff Denham, the California Republican who chairs the House Transportation Subcommittee on Railroads, Pipelines and Hazardous Materials. “Safety is of the utmost importance to the committee and our top priority moving forward.”

Denham’s reserved response was typical of several lawmakers approached this week about potential rail safety policy changes in response to the derailment and explosion in Lac-Megantic.

There have been no calls for congressional inquiries on railway safety or high-profile requests to probe the potential implications of the sudden shift to shipping crude oil by rail.

Likewise, U.S. National Transportation Safety Board officials said it is too early to discuss policy issues while the Transportation Safety Board of Canada investigates the incident.

And earlier this week, when White House spokesman Jay Carney was asked whether the administration would look at safety issues tied to shipping oil by rail, he replied that the administration was “closely monitoring the situation in Canada.” But Carney did not address the safety question and deferred to the Canadian investigation.

“Safety is the top priority at the Federal Railroad Administration,” Carney said. “The accident in Quebec Province is being investigated by Canadian authorities, and the FRA does not have jurisdiction outside of the United States.”

The incident in Quebec has competed for news coverage in Washington — and often lost that competition — with last weekend’s crash of the Asiana Airlines jetliner in San Francisco that killed three people and injured more than 180 others.

Had the accident happened about 40 to 50 miles east on Montreal, Maine and Atlantic tracks that pass through the Maine lakeside town of Jackman, the reaction in Washington likely would have been much different.

Not surprisingly, members of Maine’s delegation have been more engaged than most members of Congress, given the deadly incident’s proximity to their home state.

Michaud and Pingree — both Democrats — wrote to federal rail and transportation officials asking them to “provide a detailed accounting of the rail networks currently used to transport crude oil and other petroleum products in Maine, identifying any weaknesses in existing infrastructure, and describing best practices to address any deficiencies you find.”

The office of Maine Sen. Angus King said late Friday that the independent fully supports the upcoming inspection and is awaiting findings of the Canadian investigation “to determine if any legislative steps can be taken to correct any issues that contributed to the accident.”

Nearly 5.3 million barrels of crude oil passed through Maine last year — up from just 25,000 barrels in 2011. And that number is on the rise as more oil flows from the Bakken oil fields of North Dakota and is shipped via rail to the Irving Oil refinery in Saint John, New Brunswick.

But a 2006 study by the Maine Department of Transportation found that 92 percent of the active tracks in Maine barely had the capacity to support a modern tank car filled with oil.

Transportation officials in both the United States and Canada have repeatedly warned that the common type of tank cars involved in the Quebec derailment — known as the DOT-111 car — are more prone to punctures or leaks in accidents than more modern cars.

DOT-111 tank cars make up 69 percent of the tanker fleet in the United States and are the primary rail method for transporting both crude oil and ethanol, a much more highly volatile substance. The NTSB has repeatedly linked spills and other accidents — some fatal — to failures of the cars.

“I think we do need to take a look at the integrity of these rail cars — most of which are very old — now that they are being used to transport oil from North Dakota,” Collins said in an interview. “But this also raises the question of whether it would be far safer to transport oil by pipelines.”

Collins’ latter statement was a reference to the controversial Keystone XL pipeline, which would carry crude oil largely from Canada’s oil sands or “tar sands” fields in Alberta to refineries on the Gulf Coast. The Obama administration is currently reviewing a permit application for the pipeline’s northern section and, in the process, being lobbied heavily by both sides on the issue.

Sen. John Thune of South Dakota, the top-ranking Republican on the Senate Commerce, Science and Transportation Committee, also mentioned the pipeline when asked whether the Quebec incident raised concerns in his mind about the trend of shipping crude oil by train.

“Many of us think this is an argument for why we need to build the Keystone XL pipeline because that is a very safe and efficient way to transport petroleum,” Thune said.

Additionally, the Senate committee has asked the General Accounting Office to review the safety of the country’s U.S. freight rail system.

That review is expected to be complete in October, according to Kevin Hall, a spokesman for Democratic Sen. Mark Warner of Virginia, who chairs the Senate subcommittee that oversees rail safety.

As for the Quebec incident, Hall said Warner is monitoring the Canadian investigation.

Kevin Miller can be contacted at 317-6256 or at:

kmiller@pressherald.com

Twitter: @KevinMillerDC