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WILMINGTON, N.C. (AP) -- Hurricane Matthew was downgraded to a post-tropical cyclone Sunday morning but still had some dangerous fight left in it, dumping more than a foot of rain on North Carolina in a deluge that flooded homes and businesses as far as 100 miles inland.

What will go down as one of the most potent hurricanes on record was blamed for at least 10 deaths in the U.S. and hundreds more in Haiti. As Matthew made its slow exit off the East Coast, dozens of people - including a woman and her small child - had to be rescued from their cars as life-threatening flash floods surprised many in North Carolina.

As night fell, authorities warned people to stay off the roads until the storm had passed, and the full extent of the damage likely wouldn't be clear until daybreak. The unofficial rainfall totals were already staggering: 18 inches in Wilmington, 14 inches in Fayetteville and 8 inches in Raleigh.

The U.S. National Hurricane Center said in its 5 a.m. ET Sunday update that the center of the storm was about 30 miles southeast of Cape Hatteras, North Carolina, and had sustained winds of about 75 mph (120 kpm).

"This is a very, very serious and deadly storm," Gov. Pat McCrory said.

But in many places along the Southeast coast, the damage consisted mostly of flooded streets, blown-down signs and awnings, flattened trees and power outages.

As the storm passed and the skies cleared, people started cleaning up, reopening their businesses or hitting the beach. The power started coming back on. And all three major theme parks in Orlando, Florida, including Walt Disney World, were up and running.

Along Daytona Beach's main drag, the Silver Diner had all of its shiny metal siding ripped off the front and sides, leaving only a wood frame exposed. Next door, the front window of a souvenir shop had been blown out and the roof and ceiling torn through, leaving pieces of pink insulation dangling.

David Beasley, president of Insurance Recovery Inc., surveyed the damage and said that although it looked bad, the main strip was hit harder by Hurricane Charley and Hurricane Frances in 2004.

"This is not much compared to those two. When Charley and Frances came a large number of the commercial structure had damage. You have some commercial damage, but most of the damage to most of them is minor," he said.

On Saturday, Matthew sideswiped two of the South's oldest and most historic cities - Savannah, Georgia, and Charleston, South Carolina - and also brought torrential rain and stiff wind to places like Myrtle Beach, South Carolina.

After pounding North Carolina and drenching parts of Virginia, it was expected to veer out to sea, lose steam and loop back around toward the Bahamas and Florida, too feeble to cause any trouble.

For nearly its entire run up the coast from Florida, Matthew hung just far enough offshore that communities did not feel the full force of its winds.

Its storm center, or eye, finally blew ashore just north of Charleston on Saturday, but only briefly. And by that time, Matthew was just barely a hurricane, with winds of just 75 mph.

Within an hour of residents being allowed to return Saturday to Jacksonville Beach, Florida, David Villmow had fired up the two pizza ovens at his beachfront restaurant, The Art of Pizza. He was hoping to start serving customers in a few hours.

"We got really lucky," he said. "We could be looking at a whole lot worse. All you see are downed signs, downed fences, a few gas station sign letters missing."

In Brunswick County, North Carolina, about 100 hotel guests had to be bused to a shelter because the main walls of the Comfort Inn Suites were on the verge of collapse, and dramatic video showed Fayetteville police rescuing a woman and her small child from their car as rising waters swallowed it.

Terrell Williams said that when he went out earlier Saturday to get supplies in Fayetteville, he had to take several detours because police had blocked flooded roads in the area.

"It was raining really bad," he said. "There were some areas where you could see the water starting to overtake the bridges."

Matthew's deadly potential was made all too clear in Haiti, where the hurricane roared ashore on Tuesday with terrifying 145 mph winds. At least 470 people were reported dead in one hard-hit district alone, with other devastated areas still unreachable four days later.

An estimated 2 million people in the Southeast were ordered to evacuate their homes as Matthew closed in. By hugging the coast, the storm pretty much behaved as forecasters predicted. A shift of just 20 or 30 miles could have meant widespread devastation.

"People got incredibly lucky," Colorado State University meteorology professor Phil Klotzbach. "It was a super close call."

While Matthew's wind speed had dropped considerably by the time it hit the Southeast coast, the storm will still go down as one of the most potent hurricanes on record, based on such factors as wind energy and longevity, and one of the most long-lived major hurricanes, too.

It was a major hurricane - that is, with winds of at least 110 mph - for 7.25 days.

Hundreds of thousands of people were without power in North Carolina. Three-quarters of a million people in South Carolina were left without electricity, and 250,000 were in the dark in coastal Georgia. About 1 million people in Florida lost power.

Four deaths were blamed on the storm in Florida, three in Georgia and three in North Carolina. The deaths included an elderly Florida couple who died from carbon monoxide fumes while running a generator in their garage and two women who were killed when trees fell on a home and a camper.

Property data firm CoreLogic projected the storm would cause $4 billion to $6 billion in insured losses on home and commercial properties. That compares with Hurricane Katrina's $40 billion and Superstorm Sandy's $20 billion.

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Associated Press writers Holbrook Mohr in Orlando, Florida; Gary Fineout in Tallahassee, Florida; Terrance Harris in Daytona Beach, Florida; Mike Schneider in Jacksonville Beach, Florida; Russ Bynum in Savannah, Georgia; Martha Waggoner in Raleigh, North Carolina; Jeffrey Collins on Hilton Head Island, South Carolina; Jack Jones and Meg Kinnard in Columbia, South Carolina; and Bruce Smith in Charleston, South Carolina, contributed to this report.