After the storm passed, the dangers were not over because rivers were continuing to rise. "The inland flooding is a thing that has been almost as much a concern of mine as the coastal thing," said Gov. Chris Christie.
Christie attributed one death to the storm - a 20-year-old woman who had called police to ask for help getting out of her flooded car in Salem County was found dead in the vehicle eight hours later.
During a news conference Sunday, he also said a Princeton firefighter had died during a swift water rescue. But a spokeswoman for the governor said he had been given inaccurate information. The firefighter was in critical condition, according to the spokeswoman, Maria Comella.
Christie ordered 2,000 members of the New Jersey National Guard to help with search and rescue work as officials started to assess the damage.
There were massive evacuations in the state Saturday or even earlier as the storm raced up the Atlantic Coast toward Jersey. After the storm arrived, it appeared the crisis would last for days as rivers continued to rise and utility companies warned that some outages could last weeks.
There were reports of several rescues Sunday.
By Sunday morning, about 15,000 people were at emergency shelters across the state. Christie said New Jersey Transit buses would start returning them to the shore towns they left Friday and Saturday. But in some places in northern New Jersey where rivers were rising, new shelters were opening.
Sections of the New Jersey Turnpike and Interstate 295 were among those blocked. Even in the places where high water wasn't a problem, fallen trees were.
"Please stay in your home," Christie said on NBC's "Today Show." "With over a half a million people without power and over 250 roads closed, there is no safe place to be outside right now in New Jersey."
Forecasters and emergency management officials worried about flooding in coastal areas and on numerous inland waterways that were already higher than normal after an unusually wet August.
By early Sunday as the skies cleared, Irene had dumped more than 5 inches of rain on many parts of the state, and flood warnings were in effect for every major river in the state. Some of the highest rain totals were far inland, such as 7.7 inches reported in northwest New Jersey's Stockton.
The Raritan River, which was hit hardest by rains spun off from Hurricane Floyd 12 years ago, was seen as perhaps the state's most serious flood risk again this time. It was not expected to crest until Sunday evening.
Authorities in Essex County were using a 5-ton truck to taxi people through the water away from their homes in Fairfield, where the Passaic River was high and still rising on Sunday. Sheriff Armando Fontoura said he was readying for the river to crest Sunday night.
Nearly every other waterway in the state was seen as a flood risk. The Delaware through Trenton was high, quick-moving and strewn with big branches.
A woman called dialed 911 from her car in Salem County around 1:40 a.m., asking for help getting out as water rose, state police Sgt. Brian Polite said. Her body was found in the vehicle in Pilesgrove around 9:30 a.m.
In coastal areas, where more than 1 million residents and visitors were evacuated, there was the sense that the hurricane wasn't as damaging as feared.
But it still was damaging. Most of the two-mile boardwalk in Monmouth County's Spring Lake was wrecked.
And on Long Beach Island, an 18-mile barrier island off the coast of central New Jersey, ocean water washed onto the main road through Beach Haven, and sand from the beach was scattered along several stretched.
In the shore town of Belmar, the storm surge pushed sand and debris across the avenue that runs along the beach and deposited it as far as two blocks inland. Lifeguard equipment boxes were scattered all over the street, and dead fish were found on land.
The boardwalk, which runs the entire beachfront, was coated with a thick layer of mud and sand but appeared otherwise unscathed. "I was waiting for the storm this morning; I didn't realize it was over already," said Damien Davis of Belmar, who rode out the storm with his mother.
Christie said the direct damage cost might not be high in many areas, but the business cost would be huge as many resort towns won't be back to normal for Labor Day weekend, usually one of the busiest times of the year at the shore.
In his Pleasantville home overnight without electricity, 55-year-old Harry Webber listened to howling winds and expected to wake up and find heavy damages. While searching in vain for someplace open and selling coffee, he assessed the area just inland from Atlantic City.
"I was pleasantly surprised to see that most of my town is still in one piece," Webber said.
In Atlantic County, the biggest problems were downed trees and power lines, and debris on roads. But there were no reports of any serious structural damage or injuries. The city's casinos, which shut down Friday, were scheduled to reopen Monday.
The hurricane made landfall near Little Egg Inlet, just south of Long Beach Island, the state's longest barrier island, with 75 mph winds before 6 a.m. It turned into a tropical storm as it continued to move north along the East Coast.
It was only the third time a hurricane made landfall in the state in the last 200 years. An 1821 storm crashed into Cape May and zipped up the route of what is now the Garden State Parkway. A 1903 hurricane struck just north of Atlantic City and ripped out piers in the beach resort.
AP photographer Mel Evans in Cape May and writers Samantha Henry in Little Falls, Wayne Parry in Belmar, Bruce Shipkowski in Atlantic City, Josh Lederman in Ewing and Geoff Mulvihill and Larry Rosenthal in Trenton contribute to this report.