Irene, downgraded to a tropical storm, continued to pound the East Coast early on Sunday, causing at least 10 deaths and knocking out power to more than 3 million homes and businesses.
Five people died as a result of the storm in North Carolina, and three were killed in Virginia due to falling trees, emergency officials said, according to CNN.
A man died around noon in while surfing in New Smyrna Beach, Fla., and a woman in Queenstown, Md., died after a tree knocked a chimney through the roof of her home, officials said.
In the Washington area, roughly 500,000 homes and businesses were without power. Thousands of flights were cancelled, the Bay Bridge was closed and flooding was expected.
Washington Mayor Vincent Gray said the storm has downed dozens of trees and left 32,000 District households without electricity, but said the District appeared to have escaped any serious damage or casualties.
"Overall, this could have been awful lot worse," Gray said Sunday on ABC 7 News. "I'm pleasantly surprised; it certainly could have been worse."
Gray urged city residents to stay off the area's roads to allow clean-up crews to remove the downed trees and fallen debris. He said the biggest challenge was one the city had no direct control over: the ability of Pepco, which supplies electricity to the area, to quickly restore power to the tens of thousands of homes which are currently without power.
On Sunday at 11.30 a.m., officials including Homeland Security Secretary Janet Napolitano and Federal Emergency Management Agency Director Craig Fugate will hold a news conference on the hurricane and the government's response. FEMA and then-president George W. Bush were widely criticized for what was seen as a lackluster response to Hurricane Katrina in 2005 as it bore down on and then devastated the Gulf Coast.
President Obama, who cut short his Martha’s Vineyard summer vacation to bring his family home to the White House, has received regular briefings on the storm from federal emergency officials.
Obama visited FEMA headquarters in Washington on Saturday. "It's going to be a long 72 hours," Obama said in what has become a daily video conference with preparedness officials and others, including representatives of big-box stores signed on for emergency relief efforts.
"This is obviously going to be a touch and go," he told FEMA employees.
(PICTURES: Irene Slams East Coast)
FEMA directed people in the hurricane’s path to websites, Twitter feeds, Facebook pages, and mobile apps.
Nongovernmental organizations and companies got in on the action as well. Google and Facebook both have web pages dedicated to information about the storm.
“We anticipate heavy rain, potential flooding and significant power outages throughout the area of the storm, which means all up and down the Eastern seaboard,” Napolitano said.
D.C. officials ran out of sandbags on Saturday morning.
The hurricane had weakened and was not expected to get any stronger, said Bill Read, director of the National Oceanic and Atmospheric Administration’s National Hurricane Center.
But officials stressed that the storm is bringing hurricane-force winds, and also could generate tornados in some areas. “If you’re in a hurricane, you’re in a hurricane and it’s a big deal,” Napolitano said.
“We’re now in the middle of what could be one of the largest responses that Red Cross operations have had in recent memory,” added Gail McGovern, president and chief executive officer of the American Red Cross.
Obama declared disasters in Maryland, New Hampshire, New Jersey, Connecticut, Rhode Island, Massachusetts, New Jersey, Virginia, and New York to free up federal aid before any flooding or wind damage to and help in preparations.
DHS deployed three Disaster Medical Assistance Teams to staging areas, with doctors, nurses, paramedics, and pharmacists trained to provide emergency health and medical support.
FEMA Incident Management Assistance Teams were staged in South Carolina, North Carolina, Virginia, New York, Massachusetts, Vermont, D.C., Connecticut, Delaware, and Rhode Island.
Defense Secretary Leon Panetta issued a prepare-to-deploy order for 6,500 active duty troops, who would deploy in support of hurricane relief efforts if ordered, according to Pentagon spokesman George Little.
Little said that it has taken Panetta only 5 to 7 minutes on average to approve requests from states for Defense Department support.
McGovern said her organization was anticipating the storm would affect a "huge geographical area" and that it could take "weeks, maybe even months" to fully respond to damage and needs.
She said the Red Cross was ready to serve 250,000 meals a day, which could be increased to 1 million, and has 15,000 shelters in the affected area.