The New York City Marathon will go ahead this weekend and it will be dedicated to the victims of Superstorm Sandy and their families.
Mary Wittenberg, chief executive of the race organisers the New York Road Runners (NYRR), hopes that staging the world-famous race, just days after the devastation, will show the "vitality and spirit" of New York City (NYC).
The aim is to aid in recovery and show the city "will be back stronger than ever".
At least 63 people were killed in Monday's superstorm which battered and brought destruction to the US east coast.
Police and fire departments, and electricity and transportation organisations are still trying to get the city back on its feet.
Marathon world record holder Paula Radcliffe, a three-time winner of London and New York marathons, tweeted: "If anyone can make a marathon happen on Sunday in a city recovering from a natural catastrophe it is NYRR.
"The city needs the solidarity, the lift and the economic boost that Marathon Sunday brings to NYC.
"Thoughts go out to everyone on the east coast, Caribbean and beyond."
"There will be substantial modifications to the logistics and operations of the race" - NYRR
More than 47,000 people were due at the start line at Staten Island on 4 November, but uncertainty remains over how many will be able to make it.
Crowds of more than a million spectators, in normal circumstances, flock to the streets of New York's five boroughs to watch.
Charities are usually big winners from the fundraising efforts of many of the runners.
Last year's event brought a 340-350 million US dollars boost to New York's economy. Organisers expect a fall in numbers this year.
NYRR said "our sole focus" is now on Sunday's marathon.
The opening ceremony, which had been set to include a parade of nations in Central Park along with a spectacular fireworks display, has been cancelled.
Another linked event, a 5K dash to the finish line that would have run through Midtown on Saturday, has also been cancelled.
Opening hours for runners to pick up their race numbers and kit have been extended.
An alert has been issued for stand-by volunteers to help out. NYRR are also organising for donations to help back the relief effort to be taken.
NYRR said: "There will be substantial modifications to the logistics and operations of the race, including the transportation plan, due to the impact of the storm.
"We continue to work with the city to adjust our marathon planning."
Organisers have been pressing ahead with preparations, using a hotel ballroom as a makeshift base to check and lay out timing equipment in the hours after the storm passed.
NYRR said: "We're adjusting Marathon Day plans as a result of the storm's impact on our operations and resources.
"At every turn, we will be working to ensure that our planning doesn't affect any recovery efforts."
The race, now being held for the 43rd time, is one of highlights of the international marathon circuit, attracting a crop of the world's top racers.
Television audiences can hit 330 million.
Ms Wittenberg said the decision to stage the race was ultimately down to New York mayor Michael Bloomberg.
In the face of some criticism that the event has not been cancelled, he believes it will not overly burden the police as it is run on Sunday. Street traffic should be at a minimum, it was argued.
Many parts of the city, including Lower Manhattan, are expected to have their power back, freeing up other workers.
Mr Bloomberg told a press conference: "The city is a city where we have to go on".