Mayor Michael Bloomberg had earlier defended his decision to hold it despite heavy criticism as the city struggles back from Superstorm Sandy.
"If you think back to 9/11, I think Rudy [Giuliani] made the right decision to run the marathon," Bloomberg said at a press conference Friday. "It pulled people together and we have to find some ways to express ourselves and show solidarity to each other."
The New York City marathon is the world largest, with tens of thousands of participants. In a typical year, New Yorkers line the route's 26 miles, turning the city into a giant party.
The race winds through all five boroughs, but it starts in hard-hit Staten Island, parts of which look like a disaster zone.
"If they take one first responder from Staten Island to cover this marathon, I will scream. We have people with no homes and no hope right now," he posted on Twitter earlier in the week.
At least 19 of New York's 41 deaths occurred in the oft-forgotten borough, home to 500,000. Officials are still searching homes for survivors. The death toll in the U.S. from Superstorm Sandy neared 100 victims on Friday, as New York City reported one more death and Mayor Bloomberg warned: "There could be more fatalities."
"The prudent course of action here -- postpone the marathon, come back a different day," Manhattan Borough President Scott Stringer told TODAY's Savannah Guthrie. "Our first priority, let's help people who lost their homes, who are missing loved ones."
Stringer said downtown Manhattan, the city's financial hub, "looks like a wasteland" and is not close to being ready for the race, which goes through each of New York's five boroughs.
Bloomberg has vowed the marathon will not divert any resources from victims, and expects power to be restored to downtown Manhattan by race day. In defending his decision to go forward, the mayor cited the thousands of out-of-town visitors who come for the marathon.
Those visitors need hotel rooms, but many of them already are occupied by New Yorkers displaced from their homes. Richard Nicotra, who owns the Hilton Garden Inn in Staten Island, has refused to throw out evacuees to honor reservations for marathon runners, according to NY1.
With power scarce, the three generators set up Friday to provide electricity to the marathon's media tent in Central Park along the Upper West Side drew some attention.
The two active generators crank out 800 kilowatts of electricity, which would be enough to power 400 homes, the New York Post reported. The third unit, a backup, sits idle, in case one of others fails, the paper said.
Paul McCarthy, 43, who lives nearby, was walking his dog down Central Park West on Friday as marathon workers and runners whizzed by him.
"I woke up this morning and a lot of people on my Facebook page were saying they should shut it down, but my neighbor just reminded me that a third of the runners come from overseas. So logistically, they wouldn't be able to reschedule it, I don't think," he said. "Maybe it would be a good thing for the city just to get something positive going."
Manhattan Borough President Scott Stringer tells TODAY's Savannah Guthrie he believes Mayor Bloomberg should postpone the New York City marathon as congressman Michael Grimm from Staten Island says he's "angry" over plans to continue with the race
His overall assessment of holding the marathon on Sunday: "Slightly net positive."
Alberto Eguiguren, 48, a runner from Chile, arrived Thursday night with his two brothers, also marathon runners.
"It shows how the American people are always fighting to have a better country. Even though there was a disaster over the weekend, the people are ready -- not only for the local people but the international, too. We're here because we really like the States, we really like New York. We really feel it's one of the best places to run a marathon.... There are a lot of people with damages, but the stores are open, the streets are working. It's amazing."
But others are less approving of Bloomberg's decision.
A Facebook page called "Cancel the 2012 NYC Marathon" had more than 27,000 likes and growing on Friday morning. Claiming to be started by a New York City resident, the page says, "The last thing NYC needs at this time is an extra 100,000 people or so flooding our already devastated streets. Things are not back to normal. Our city is working hard enough to recover please do not complicate things with a race."
One commenter suggested Bloomberg should "postpone [the race] for a month or so and then use the race as a perfect platform to showcase how ALL 5 BOROUGHS have recovered. That shows resilience, and RESPECT for the citizens who have suffered, without foregoing the economic benefits of the race."
Another commenter asked, "Who would ever want to go to a war zone to run a marathon?"
The New York Road Runners, which organizes the marathon, said the event will bring $340 million to the city. The club also announced on Thursday that it will donate at least $1 million, or $26.20 for each of the more than 40,000 runners expected to participate, to aid New Yorkers affected by Sandy.
The Rudin Family, one of the founding members of the marathon, said it would donate $1.1 million and the ING Foundation said it would give $500,000.
Superstorm Sandy made landfall Monday evening on a destructive and deadly path across the Northeast.
"We're not looking to be a drain on any of the city resources," NYRR spokesman Richard Finn told Reuters. NYRR had hiked the race fee this year, in part to pay police overtime.
The marathon will shut down more than 20 miles of city roads and typically requires more than 1,000 police to man the route.
"Things are everything but normal for so many people," said Patricia Profita, a teacher who lives in the Great Kills neighborhood of Staten Island. "People should not be running through the boroughs, but instead running to aid those people."
The NYRR club announced on its Facebook page last night that this year's marathon is dedicated to the City of New York, the victims of the hurricane and their families.
One commenter, Scott Cohen, 52, who is running his 18th New York City Marathon in a row, admitted it "seems frivolous in light of the death, disruption and despair in parts of the city."
Still, the fitness trainer expects that by Sunday most New Yorkers will be supportive. "The race has always been a 26.2 mile block party and the city feels the love."
Reuters contributed to this report.