In a crowded pack of mayoral candidates, agreement on the issues might seem to be the path least likely to lead to Gracie Mansion. But Sunday’s subway fire has brought just such a consensus.

Standing before a phalanx of cameras and microphones outside the A train station at Jay Street in downtown Brooklyn, the City Council speaker, Gifford Miller, repeated a refrain heard throughout the city since service on the A and C lines, which carry more than half a million riders a day, was disrupted by a fire that gutted a room filled with relays that control the safe flow of trains.

“I know it’s been said before by other people,” the Democratic mayoral hopeful said, “but it really is scary when you think that this was done inadvertently. What about all those people out there who want to do this on purpose?”

Mr. Miller, who was joined at Jay Street by other council members, later said: “Clearly this ought to serve as a wake-up call for the need to update the signal system, not just on these lines but all over the city. But the first thing is to make sure service is up and running for subway riders.”

Stopgap measures to ensure riders can still get home are well under way, transit officials said. Police, who are still investigating the incident, do not suspect the fire was a terrorist act. But healing what ails the country’s largest subway system, now more than 100 years old, is a complicated task.

It is one that is likely to extend beyond that far-off time in November when, coincidentally, C service as well as A service should be restored to normal frequency, and New Yorkers go to the polls to elect a mayor.

And it is a task that city government has little to do with: The state-run Metropolitan Transportation Authority is in charge of New York City Transit, the agency that operates the city’s subways and buses.

Mr. Miller called on the MTA to allow commuter vans, express buses, and shuttle vans to pick up passengers along affected routes.

A New York City Transit spokesman, Charles Seaton, said such measures by now are unnecessary. V trains are running in Brooklyn along the C-train corridor from Jay Street to Euclid Avenue. And B trains are picking up the slack on the Manhattan side.

In the aftermath of the subway fire, the council’s transportation committee scheduled a hearing for next Thursday to investigate the cause of the accident and the vulnerability of the system to attacks.

“If this equipment was so critical, why wasn’t it safeguarded?” the chairman of the committee, Council Member John Liu of Queens, said. “There needs to be a public accounting of what happened.”

Representatives of New York City Transit will probably be there to testify, Mr. Seaton said.

A long-term solution for the system’s vulnerability to disruption is much more elusive, even as confidence in the system ebbs and frustration heightens. Riders face the second fare hike in two years next week, as another mayoral candidate, Manhattan Borough President C. Virginia Fields, pointed out.

Riders, she said in a statement, “need to believe that their hard-earned money is being spent wisely to maintain and upgrade the system.” She did not elucidate how that might happen.

Mr. Miller called upon the governor to declare a state of emergency, which would free up funds and speed the contracting and design process, he said yesterday.

Governor Pataki won’t be doing so because the MTA already has the authority to award contracts on a “fast track,” a spokeswoman for the governor, Lynn Rasic, said.

The mayoral candidates agreed that updating the subway’s technology, which may enable backup systems to reduce service disruptions, is a priority.

Getting it done – irrespective of the logistical issues of updating a system that serves more than 8 million riders a day and contains 722 miles of subway track from lines of various vintages – is a problem the candidates have begun to address, if only rhetorically, as a result of the fire.

The two Democratic candidates from Brooklyn, Charles Barron, a city councilman, and Anthony Weiner, a congressman, both said the MTA’s power should be diminished, though that did not mean they were in favor of privatizing the city’s transportation systems.

Another mayoral candidate, a former Republican council member, Thomas Ognibene of Queens, did not respond to calls seeking comment.

Speaker Miller, meanwhile, called the MTA “a monopoly” and said: “It’s acting as if people don’t have any choice, and the worst part here is that people really don’t have any choice.” An aide to Mr. Miller said he did not mean the MTA should be disbanded and privatized.

Even if the MTA is state-run, during this political season the subway fire was seized as an opportunity to criticize the mayor.

“The MTA should use their scarce resources to build up the system and keep the fare down, instead of cutting secret deals to help Mayor Bloomberg build a West Side stadium for a billionaire team owner from New Jersey,” the Democratic front-runner, Fernando Ferrer of the Bronx, said in a statement issued by his campaign. The other Democratic candidates also have opposed the plan supported by the Bloomberg administration to help finance a Jets stadium to be built over MTA rail yards at the Hudson River.

Mr. Weiner, who is on the House Transportation and Infrastructure Committee, said he has already secured funds for three ferries that would take commuters in the Rockaways – an area that depends on the A and C lines – from Jamaica Bay to Manhattan via the waterways. He’s also included funds in a transportation bill to create express bus lanes, the Democrat said. But first he would take on the MTA.

“If I were mayor I would wage a huge battle to wrestle authority away from the MTA,” Mr. Weiner said. “When so much of our state is in their hands, there is not the same amount of accountability.”

The mayor, in his State of the City address last week, criticized the governor for not giving the MTA enough financing.

Mr. Barron, who referred to the MTA as a “quasi-government” that operates without the oversight of an electorate, proposed creating a temporary state and city commission to oversee the MTA’s finances and operations. He suggested implementing a 2-cent transaction tax for stock that is bought and sold on the city’s capital markets.

“This is a deeper issue,” Mr. Barron said. “The infrastructure is antiquated. We need to make sure we generate capital so we can secure and fix the MTA. Because it’s out of control.”