Eliot Brenner of the Nuclear Regulatory Commission told CBS News that the fire is out and there was no release of any harmful material.
"The plant is stable and reacted normally," he said. "There's no impact on public health and safety."
The fire was outside the nuclear area of the plant and there was no release of radiation, said Diane Screnci of the Nuclear Regulatory Commission. She also said the fire was out.
The NRC, the federal agency which monitors nuclear power plants, said the Indian Point Plant officially declared "an unusual event" at 11:43 a.m., several minutes after the fire had been put out. An "unusual event" is the lowest level type of alert that is reported to federal regulators, reports CBS News correspondent Bob Orr.
Jim Steets, a spokesman for Indian Point owner Entergy Nuclear Northeast, said there was smoke around the area of the transformer yard, which is across a street from the plant in Buchanan.
"If there's a fire in the transformer, the plant is designed to shut down," he said.
He said he did not know the cause of the fire.
Screnci said the plant shut down automatically.
Indian Point 2, the other working nuclear plant on the site, remained up and running, Steets said.
He said the transformer is a component that takes electricity produced by the plant and transforms it for use by the metropolitan area's electrical grid.