WASHINGTON — After a string of deadly train crashes, a pair of angry US senators stood in New York City's Grand Central Terminal four months ago to denounce the Federal Railroad Administration as a ''lawless agency, a rogue agency.''
They said it was too cozy with the railroads it regulates and more interested in ''cutting corners'' for them than protecting the public.
In the past two months, photos of rail cars strewn akimbo beside tracks have rivaled mountains of snow in Boston for play in newspapers and on television.
But the reaction by Congress to the railroad oversight agency's performance has been extremely positive recently.
Accolades were directed at its acting head, Sarah Feinberg, even though her two-month tenure in the job has coincided with an astonishing number of high-profile train wrecks:
■ Feb. 3: Six people were killed when a commuter train hit an SUV at a grade crossing in Valhalla, N.Y.
■ Feb. 4: Fourteen tank cars carrying ethanol jumped the tracks north of Dubuque, Iowa, and three burst into flames.
■ Feb. 16: Twenty-eight tank cars carrying crude oil derailed and caught fire in West Virginia.
■ Feb. 24: A commuter train derailed in Oxnard, Calif., after hitting a tractor-trailer at a grade crossing.
■ March 5: Twenty-one tank cars derailed and leaked crude oil within yards of a tributary of the Mississippi River in Illinois.
■ March 9: The engine and baggage car of an Amtrak train derailed after hitting a tractor-trailer at a grade crossing in North Carolina.
At first glance, Feinberg seems an unlikely choice to replace Joseph Szabo, the career railroad man who resigned after five years in the job. She is 37, a former White House operative, onetime spokeswoman for Facebook's Mark Zuckerberg, and, most recently, chief of staff to the US Department of Transportation secretary.
Nothing on her résumé says ''railroad.''
''Sometimes it's good to have an outside person,'' said Senator Charles Schumer, Democrat of New York, who got a call from Feinberg immediately after the Feb. 3 crash in Valhalla. ''She's smart, she's a quick study, she knows how to bring people together. I think she's the right person for the job.''
''Whether she's had a lifetime experience riding the rails or working on the rails, she knows how to get to the crux of things and move things forward,'' said Senator Joe Manchin III, a West Virginia Democrat who arrived at the Feb. 16 crash shortly before Feinberg did. ''I was very impressed.''
Schumer calls Feinberg ''hard-nosed'' and says she isn't worried if she ruffles some in an industry grown accustomed to a more languid pace of change.
After the Valhalla crash, Feinberg pulled together a team to come up with a better way to address an issue that kills hundreds of people at grade crossings each year.
''We're at a point where about 95 percent of grade-crossing incidents are due to driver or pedestrian error,'' Feinberg said. ''While I don't blame the victims, this is a good example of a problem that needs some new thinking.''
A month later, she called on local law enforcement to show a greater presence at grade crossings and ticket drivers who try to beat the warning lights. Next, the railroad agency says it plans ''to employ smarter uses of technology, increase public awareness of grade crossing safety, and improve signage.''
''When it comes to the rail industry, that is lightning fast, and it's really impressive,'' said a congressional aide who focuses on transportation.
Grade-crossing deaths pale in comparison to the potential catastrophe that Feinberg says keeps her awake at night. ''We're transporting a highly flammable and volatile crude from the middle of the country, more than 1,000 miles on average, to refineries,'' she said.
All of the recent crude-oil train derailments happened miles from the nearest town. But little more than a year ago, a CSX train with six crude-oil tank cars derailed on a river bridge in the middle of Philadelphia. And an oil-fueled fireball after a derailment in Lac-Mégantic, Quebec, in July 2013 left 47 people dead.
The number of tank-car trains has expanded exponentially since the start of a production boom centered in North Dakota. Seven years ago, 9,500 tank cars of Bakken crude traveled by railroad. Last year, the number was 493,126. In 2013, an additional 290,000 cars transported ethanol.
Mindful of the potential for disaster, the White House tasked the Office of Management and Budget and the Transportation Department with figuring out how to safely transport the oil. At DOT, that fell to Feinberg, who had just signed on as chief of staff to Secretary Anthony Foxx.
''We found her to be very hands-on, firm but fair, and ready to work with all stakeholders in making fact-based decisions,'' said Ed Greenberg of the Association of American Railroads. ''She is someone who has quickly recognized the challenges in moving crude oil by rail. And the freight rail industry is ready to work with her" in her new role at the Federal Railroad Administration, he said.