Risks are many from Irene's wrath: surging seas, drenching rains, flash floods and high winds are all possibilities the Federal Emergency Management Agency director wasn't counting out.
"We're going to have damages, we just don't know how bad," Craig Fugate told AP as FEMA readied plans in many states. "This is one of the largest populations that will be impacted by one storm at one time."
Not just infrastructure, but jobs are also at stake.
Take Mary Thomas of Nags Head, a 34-year-old motel worker.
"We depend on tourism," said Thomas. "If we're hit, the motel will be shut down for a while. Businesses will be closed. People will have to rebuild. And that means I'll be out of a job."
The Outer Banks attracts thousands of tourists each year who stay in hotels and motels or the upscale homes lining the oceanfront. Many workers, like Thomas, earn a living by working in restaurants that cater to the tourists — and some were struggling before the storm barreled toward North Carolina.
"I just don't know what I would do if I lose my job," said Thomas, the mother of two.
Latest forecasts had Irene crashing up the North Carolina coastline Saturday, then churning up the East while drenching areas from Virginia to New York City before a much-weakened storm reaches New England.
Even if the winds aren't strong enough to damage buildings in a metropolis made largely of brick, concrete and steel, a lot of New York's subway system and other infrastructure is underground and subject to flooding in the event of an unusually strong storm surge or heavy rains, authorities noted.
New York City's two airports also are close to the water and could be inundated, as could densely packed neighborhoods, if the storm pushes ocean water into the city's waterways, officials said. The city had a brush with a tropical storm, Hanna, in 2008 that dumped 3 inches of rain in Manhattan.
All told, Irene could cause billions of dollars in damages or more along the Eastern Seaboard in a worst case scenario, said Kathleen Tierney, director of the Natural Hazards Center at the University of Colorado.
In the last 200 years, New York has seen only a few significant hurricanes. In September of 1821, a hurricane raised tides by 13 feet in an hour and flooded all of Manhattan south of Canal Street, the southernmost tip of the city. The area now includes Wall Street and the World Trade Center memorial.
New England is also unaccustomed to direct hits from hurricanes. Griffin, who fishes from Portland, Maine, still recalls the clobbering when Hurricane Gloria struck in 1985 and said this one is not one to ignore after years without a large, dangerous storm.
"We have a young generation of lobstermen who've never experienced a full-blown hurricane," Griffin warned.
The first U.S. injuries from Irene appeared to be in South Florida near West Palm Beach where eight people were washed off a jetty Thursday by a large wave churned up by the storm.
In Washington, Irene dashed hopes of dedicating a 30-foot sculpture to the late Martin Luther King Jr. on the National Mall on Sunday with the help of President Barack Obama. While a direct strike on the nation's capital appeared slim, organizers said the forecasts of wind and heavy rain made it too dangerous to summon a throng they initially expected to number up to 250,000 strong.
CoreLogic, a company that provides strategic information to businesses and others, issued a statement Thursday that its data showed some 1.8 million residential and commercial properties in the region were at potential risk to storm surge flooding. It said those properties are in 12 major coastal metropolitan areas within Irene's projected path and added Long Island, New York, faced the highest risk with nearly 388,000 properties.
Heavy rain and possible floods were big worries in the Northeast. The potential for flooding and wind damage are Irene's greatest threats to Rhode Island, still smarting from the 2010 spring floods that devastated parts of the Ocean State.
In Connecticut, Gov. Daniel P. Malloy declared a state of emergency and warned there could be prolonged power outages if Irene dumps up to a foot of rain on already saturated ground as some fear. He said emergency responders must be ready in event of any evacuations from heavily developed urban areas.
"We are a much more urban state than we were in 1938," he said, referring to the year that the so-called "Long Island Express" hurricane killed 600 people and caused major damage with 17-foot storm surges and high winds.
The urban population explosion in recent decades also worries New Jersey officials. Gov. Chris Christie encouraged anyone on that state's heavily built-up shoreline to begin preparations to leave.
Hurricanes have made landfall on New Jersey just twice in the last 200 years, in 1821 and 1903, the latter battering the Atlantic City area. But the state now has 8.8 million people and coastal areas packed with homes and businesses — and 11 major casinos in Atlantic City.
The beach community of Ocean City, Md., was taking no chances, ordering thousands of people to leave.
"This is not a time to get out the camera and sit on the beach and take pictures of the waves," said Maryland Gov. Martin O'Malley.
Associated Press writers Michael Biesecker in Raleigh, N.C.; Jennifer Peltz and Seth Borenstein in New York; Wayne Parry, Geoff Mulvihill and Bruce Shipkowski in New Jersey; Brock Vergakis in Virginia; Randall Chase in Ocean City, Md.; and Martha Waggoner in North Carolina contributed to this story.
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