In Prattsville, N.Y., 21 people were trapped in a hotel as floodwaters surrounded the building. The group reportedly included two pregnant women, seven toddlers and three babies.
According to Dan King at the Greene County Office of Emergency Management, the New York National Guard plucked the people from the water-logged hotel and took them to a shelter, but some still remained early today.
"The water is receding on the mountaintop. The last several people who needed to be extracted from homes that had been blocked from water actually walked out. There are still some people who are isolated in their homes. They cannot get out," he said.
Just east of the town of Prattsville, the town of Windham, N.Y., was "wiped out" by flooding, with four feet of water rushing through Main Street, said Michael Scarey, the town's fire chief.
Hammering rains that started Saturday night dumped more than 10 inches of water on the village, forcing evacuations, submerging school buses and garages and shutting off access to the rest of the mountaintop.
New York City was virtually shut down over the weekend for fear that Irene would be a killer storm. The city ducked the worst that Irene had to offer, but struggled today with a morning rush hour with limited subway and commuter rail service.
City's airports were back in business today, and Atlantic City's casinos were quick to resume gambling.
In Philadelphia, perhaps the worst-hit city, the storm dumped 5.7 inches of rain within 18 hours -- more than the area usually gets in a month. On Sunday the Schuylkill River, which runs straight through Philadelphia, crested at its highest level since 1869, flooding homes and businesses.
In a statement from the White House Sunday afternoon, Obama warned of the long recovery in Hurricane Irene's aftermath.
"This is not over," Obama said, urging residents to comply with local authorities. "The impacts of this storm will be felt for some time. And the recovery effort will last for weeks or longer."
The Associate Press contributed to this report.