While Mayor Bloomberg said he hopes Consolidated Edison would be able to prevent future blackouts like the one that hit an estimated 100,000 residents this week, he acknowledged that they might just be inevitable.

“It may be just one of those things that there’s not a lot that we can do, that we always will, every few years, have something like this,” he said.

By last night, about 120 customers — according to one metric, one “customer” equals three or four people — were going on their ninth day without power. Con Ed has restored service to more than 24,000 customers, a company spokeswoman said.

Now that power is almost entirely back, city number crunchers, insurers, and lawyers are beginning to tally the economic impact of the eight-day outage.

City officials haven’t calculated how much the blackout cost Queens businesses, a spokesman for the city Small Business Services Department, David Garlick, said.

Assemblyman Michael Gianaris, whose district was hit, said the number could be tens or hundreds of millions of dollars.

“Do the math,” Mr. Gianaris said. “It adds up pretty quickly.”

Over the past week, the city’s Small Business Services Department has gone door to door to about 750 businesses to gather data to quantify the economic damage, Mr. Garlick said.

When the electricity failed early last week across most of northwest Queens, the store manager of a Sunnyside Key Food supermarket scrambled in the dark to salvage whatever perishables he could stash in dry ice before renting a $3,000-a-week power generator.

The food Raied Zahriyeh couldn’t preserve — tens of thousands of dollars of meat and frozen goods — he had to junk.

“We lost a lot of merchandise,” Mr. Zahriyeh said outside his store on Queens Boulevard, a block that was until yesterday was lined with bulky generators.

The head of the Steinway Street Business Improvement District, Tony Barsamian, said it may be difficult to get an accurate estimate of the economic loss from the blackout. With businesses closing and employees losing out on paychecks, the scope of the losses probably had a major ripple effect.

“They don’t get their paycheck, they’re not going out to dinner,” Mr. Barsamian, the owner of a local newspaper, whose employees worked on a sidewalk because the newsroom had no electricity, said. “That’s business that’s lost forever,” he added.

Mr. Zahriyeh said the Key Food franchise expects to record a 10% drop in business — totaling more than $30,000.

The store’s management is in the process of filing compensation claims with Con Ed, but the $7,000 maximum the utility will pay damaged businesses won’t come close to reimbursing the $300,000 that Mr. Zahriyeh estimates the blackout will cost his three Key Food stores in the area. Residents had similar complaints about the $350 reimbursement Con Ed is offering to cover their expenses for spoiled food.

One Sunnyside resident, Sandra Boyle, announced a lawsuit yesterday against Con Ed for unspecified damages, charging that the utility giant ignored suggestions made by New York’s attorney general, Eliot Spitzer, in the aftermath of an outage that blacked out Inwood and Washington Heights for less than a day.

Ms. Boyle’s lawyer, Brian O’Dwyer, said he is confident jurors will find Con Ed was grossly negligent.

“That verdict will not be, ‘Thank you, Con Ed,’ but will be ‘Guilty as charged’,” Mr. O’Dwyer said, adding that he said he’s expecting other New Yorkers to sue Con Ed.

To win, Ms. Boyle, whose power was restored yesterday, and other potential litigants will have to prove that Con Ed was not only careless, but that it didn’t exercise “even slight care” or displayed willful misconduct.

That’s a high hurdle, a former chairman of the state bar’s Public Utility Law Committee in Albany, Andrew Gansberg, said.

“It wouldn’t surprise me if there are a lot of lawsuits,”Mr. Gansberg, who has represented the utility companies, said.

Mayors Koch and Giuliani, who each presided over major blackouts — in 1977 and 1999 — have sued Con Ed in the past.

Mr. Bloomberg’s recent praise for Con Ed’s CEO, Kevin Burke, indicates that he will not.

His defense of Con Ed was met with ire from three Queens elected officials who represent the area. The lawmakers rolled their eyes and snickered on Monday at a news conference with Mr. Bloomberg when he started to thank Mr. Burke for his hard work.

Mr. Bloomberg didn’t directly address in public the politicians’ behavior, saying only that critics have the right to their opinion.

The mayor’s office didn’t return calls inquiring about potential litigation by the city against Con Ed.

The city was among thousands of plaintiffs that sued in the wake of the 1977 blackout that plunged the five boroughs into darkness.

Although some judges faulted Con Ed, thousands of those lawsuits were eventually dismissed because the attorneys couldn’t prove the utility was grossly negligent. One of these attorneys was Mr. O’Dwyer, who was 32 at the time.

A City Council committee plans to question Con Ed officials at a hearing tomorrow about the outages.