Metro General Manager Paul J. Wiedefeld, left, announces that subway service will be shut down for a full day so the agency can conduct emergency safety inspections. At center is D.C. Council member and Metro board chairman Jack Evans. (Evan Vucci/AP)

With a new boss running Metro — a general manager untainted by the agency’s long history of mistakes — and a new board chairman who is far more assertive than his recent predecessors about the “unconscionable” lack of dedicated public funding for subway operations, you have to wonder:

Was Wednesday’s unprecedented safety-related shutdown of Metrorail just a one-off startling event or a hint of further remarkable, disruptive steps to come?

For a beleaguered transit agency chronically addled by inertia as it labors to make a course change for the better — an organization guided less by nimble management over the years than by an ever-growing mountain of pricey consultants’ reports — will last week’s stunning decisiveness eventually seem, well, not so stunning?

Will drastic action become the new Metro normal?

If nothing else, the surprising shutdown, and what the boss and the board chairman had to say about it, announced a fresh style of leadership, a break from the static past.

General Manager Paul J. Wiedefeld, in his fourth month as Metro’s chief executive, was mostly applauded (but also jeered) for summarily halting the region’s busiest form of public transportation for 24 hours, to allow inspectors to search for dangerously deteriorated power cables along 100 miles of subterranean tracks.

Since the birth of Metrorail, 40 years ago this month, the agency had never before ordered a subway closure on a fair-weather workday. Hundreds of thousands of regular riders, given only half a day’s notice, had to scramble for travel alternatives.

“That could be a sign of a new approach that transit agencies are going to take,” said Robert Puentes, a senior fellow at the Brookings Institution’s Metropolitan Policy Program. Comparing Wiedefeld’s shutdown decree to the Chicago Transit Authority’s decision to close about 10 miles of its subway for five months of rebuilding in 2013, Puentes said, “These may be the kinds of extraordinary steps that are needed.”

Puentes said of Wiedefeld: “Because he’s a relatively new GM, he’s able to take this extraordinary step, which really highlighted the problem. . . . This became national news, and if that was part of the calculation, it was a pretty shrewd move. . . . It sends a strong signal that these kinds of things are going to be happening in the next few years.”

Passengers average about 712,000 trips each weekday on Metrorail. Asked whether long-suffering riders will witness other extreme measures as he works to revive an agency plagued by financial woes, safety and service breakdowns, infrastructure attrition, and mismanagement, Wiedefeld replied, “I hope not.” But he wouldn’t rule it out.

A look inside the smoke and fire defects that paralyzed D.C. Metro

“The key is that we create the kind of culture, the kind of organization, so we don’t get to this point,” he said Wednesday, pausing for an interview on a hectic morning for the agency, with 22 inspection crews fanned out across the idle rail network. “It’s basically about making [sound] decisions day to day,” he said. “That prevents you from having to make these kinds of decisions,” like shuttering the nation’s second-busiest subway.

A career transportation manager, Wiedefeld is a former head of the Maryland Transit Administration and chief executive of Baltimore-Washington International Marshall Airport. His retired Metro predecessor, Richard Sarles, was a seemingly reluctant public figure, a manager rooted in the arcana of nuts-and-bolts engineering. Wiedefeld is a more animated presence. But he has no extensive technical training.

“When I’m here a hundred days, and I find something, I can’t just go on, business as usual,” he said. He was referring to a tunnel fire about 4:30 a.m. Monday, before the subway opened, that raised urgent concerns about the safety of the system’s 600 “jumper cables,” a type of heavy-duty electrical line. “It starts with me,” he said of his swift, emphatic response. “But that’s what we have to basically get the culture to be.”

In addition to inspecting the 600 jumper cables, the tunnel crews also checked the condition of hundreds of heavy, elbow-shaped connection assemblies, called “boots,” that are used where power lines are attached to one another. The workers found fire hazards, mainly involving damaged or worn-out insulation, in 26 locations.

If Wiedefeld, in closing the subway, also was sending a message to the public that Metro needs more significant and predictable funding from local jurisdictions to avoid future mass inconveniences, he wasn’t alone in doing so.

D.C. Council member Jack Evans (D-Ward 2), who joined Metro’s governing board early last year and became chairman two months ago, stood with Wiedefeld at press briefings before and during the shutdown, endorsing the general manager’s decision.

Evans’s two immediate predecessors, Mortimer Downey and Tom Downs, are longtime transportation technocrats acclimated to the glacial processes of public administration, each more comfortable with planning documents than news cameras. By contrast, Evans is a media-savvy politician who seizes every chance, often on TV, to cajole Washington-area officials to boost their investments in the transit system.

Having lost two campaigns for D.C. mayor, in 1998 and 2014, Evans has made himself mayor of the subway instead. This was evident last week, when he repeatedly linked the shutdown to the region’s hesitancy to fully “do its part to support Metro.”

“It’s very important that everyone remember what happened today, and everyone participate in investing in our future,” he told reporters Wednesday, after Wiedefeld had discussed the inspections that were underway, including locations where poorly maintained high-voltage wires, shorn of insulation because of age and wear, posed a fire hazard in tunnels. “We need to establish a dedicated funding source,” Evans declared.

When the transit system was younger, the issue of dedicated funding was a frequent topic of debate. But the idea, fraught with political complications, never went anywhere, and discussions eventually faded — until Evans started banging his fist.

“Here I stand, 25 years later,” he said at one of Wiedefeld’s briefings. “And no progress has been made on the issue. That is unconscionable.”

He said of the shutdown, “We’re sorry this had to happen, that it has come to this.”

Advocates for Metro have complained that the agency, in paying for daily operations, suffers a unique financial disadvantage among major U.S. transit systems because it lacks a significant, dedicated source of money, such as a portion of a sales or gas tax. But local politicians fear that proposing higher taxes would anger voters. Instead, Metro must seek annual operating subsidies from the District, Maryland and Virginia.

The jurisdictions, which are chipping in $845 million this year, were reluctant to boost their contributions next year, despite Metro’s rising costs. Partly as a result, the agency set its next operating budget at $1.74 billion, down 3 percent from this year. Metro budgets a similar sum for annual capital projects, helped by federal funds.

Evans has pledged to lead a battle to persuade Congress to provide a dedicated stream of funding for Metro operations, in addition to the capital-improvements money. He and other local leaders, including U.S. Rep. Gerald E. Connolly (D-Va.), argue that Congress has an obligation to do so because Metro ferries many thousands of federal employees and visitors to the capital city.

“Metro is us,” Evans said. “We are Metro, all of us.”

As for Wiedefeld, asked whether Wednesday’s drama also was meant as a message to complacent transit workers that there’s a new sheriff in town, he said: “It wasn’t a designed message. It is how I manage. So they will understand that.”

His shutdown order contrasts sharply with what happened a year ago, not long after Sarles retired, when Metro was under interim leadership and federal safety officials issued a public warning about the jumper cables.

On Jan. 12, 2015, an electrical malfunction ignited a fire on tracks near Metro’s L’Enfant Plaza station, filling a tunnel with smoke. Scores of passengers on a stalled train were sickened and one died of respiratory failure. Early in an investigation that is still not complete, the National Transportation Safety Board said the meltdown involved jumper cables. The panel urged Metro to perform a system-wide inspection of the cables.

In a March 2015 memo to Metro board members, the agency’s since-departed chief engineer outlined what he planned to do in the following weeks, including: “Provide an engineering and operations report on all . . . jumper cables in tunnel sections for condition and installation. Note: Metro personnel will conduct inspections, looking for wear and tear on cables and assess the condition of cable installations.”

How careful those promised inspections were is a mystery at the moment, at least publicly. “There’s a whole lot more I have to do to find out how we got to this position,” Wiedefeld said. But clearly, last year, Metro’s top brass didn’t think the cable situation was urgent enough to warrant drastic measures.

Then came Monday’s electrical fire in a tunnel near the McPherson Square station. Although it occurred about a half-hour before the subway’s 5 a.m. opening, there were major delays on three rail lines throughout the day and evening while repairs were made and Metro tried to determine the cause of the meltdown.

It turned out to be malfunctioning jumper cables — frighteningly similar to what precipitated the L’Enfant Plaza tragedy. Officials said they were fortunate that the subway hadn’t yet opened Monday morning. The smoke near the McPherson Square station was as thick and widespread as the noxious fumes near L’Enfant Plaza, maybe more so.

This time, Metro reacted quickly.

Late Tuesday, moments after Wiedefeld broke the news of the impending shutdown, a reporter, sounding incredulous, asked, “There’s no way this can be held off to the weekend?” And the general manager replied: “From where I sit, the safety of the public and my employees is paramount. So to risk that, I just cannot.”

Which might ring familiar to John Porcari, a former Maryland transportation secretary who worked closely with Wiedefeld in Maryland a decade ago. “He really means it about safety,” Porcari said. “He literally stays awake nights thinking about safety.”

Wednesday afternoon, in announcing that the subway would reopen the next morning, Wiedefeld described the damaged jumper cables that inspectors had fixed or replaced. Three sets of cables (near the McPherson Square, Farragut West and Potomac Avenue stations) were in such bad shape, with exposed high-voltage wires, that Metro would not have run trains over them if officials had been aware of the problems.

“Show-stoppers,” the inspectors dubbed those cables.

Overall, the 26 places with faulty cables and boots were along the most heavily traveled stretch of the rail system, between the Rosslyn and Stadium-Armory stations, where trains on the Orange, Blue and Silver lines share tracks beneath downtown Washington.

In the interview Wednesday, while untold thousands of straphangers were relying instead on cars, buses, bikes and walking shoes, Wiedefeld vowed to get to the bottom of what happened with last year’s jumper cable inspections — as soon as he can find the time.

“Right now, I’m focusing on the immediate issues at hand,” he said. “I have a very stressful situation going on. . . It’s a huge thing we’re dealing with.”

He said, “I’ve got a lot on my mind.”

Mary Pat Flaherty contributed to this report.