WILKES-BARRE, Pa. — Up to 70,000 people from the area inundated by Hurricane Agnes nearly four decades ago were ordered to evacuate Thursday as widespread flooding brought on by the remnants of Tropical Storm Lee lashed on already waterlogged Pennsylvania and was blamed for four deaths.

Up to 7 inches of heavy rain came a little more than a week after Hurricane Irene moved through the state. The soaking sent numerous small waterways over their banks, including one northern Pennsylvania creek that undermined a bridge abutment, causing a partial collapse.

Luzerne County officials called for a mandatory evacuation of all communities along the Susquehanna River that were flooded in the historic Agnes deluge of 1972 — an order affecting tens of thousands of residents.

Luzerne County Emergency Management Agency official Frank Lasiewicki told The Associated Press the river is projected to crest at nearly 41 feet — the height of the levee system protecting riverfront communities including Wilkes-Barre and Kingston — between 4 p.m. and 8 p.m. Thursday. The Susquehanna River reached 40.9 feet during the historic Agnes flood of 1972.

Residents were ordered to leave by 4 p.m.

Luzerne County officials were seeking volunteers to lay sandbags on both sides of the Susquehanna, which emergency management director Stephen Bekanich said was rising at a rate of three-quarters of a foot an hour.

Officials believed the levees would contain the river.

In places unprotected by the levee system, however, emergency officials expect catastrophic flooding of 800 to 900 structures. Flood stage in many of those half-dozen municipalities is 23 feet, meaning they could be inundated with 19 feet of water. Officials say they expect the river to crest above rooftops.

"We're confident the levees are going to work," Bekanich said Thursday morning.

But if the Susquehanna overtops the levee system, 10,000 structures throughout the Wyoming Valley could be flooded, said Bekanich.

"If we, God forbid, overtop the levee system, we're looking at catastrophic damage throughout the whole county that borders the river communities," he said. "This is a scary situation."

Bekanich, who himself lives in a riverfront community, has been working emergency management in Luzerne County for 23 years and said: "This is the worst I've ever seen."

Wilkes-Barre Mayor Tom Leighton told residents to "prepare themselves for an extended evacuation" of 72 hours.

Leighton, who ordered about 20,000 residents to evacuate, advised them to take clothing, food and prescription medicine. He also asked city businesses to shut down by noon.

"There is no need to panic," he said. "This is a precautionary evacuation and the safety of our residents is our biggest concern. We have prepared for this type of emergency and we are ready to respond to whatever comes our way over the next 72 hours."

In Union County, several homes along the Susquehanna were already evacuated, including parts of downtown Lewisburg, about 70 miles southwest of Wilkes-Barre.

County emergency operations manager Stan Hudson said much of Lewisburg was shut down.

"We're going to be flooded in," Hudson said. "We're going to be stuck here for a while."

Members of the Pennsylvania National Guard have been assisting in evacuations and blocking off flooded roadways. Guardsmen have flown about 30 missions, mostly evacuations, across central and northeastern Pennsylvania, said Sgt. Matt Jones.

At least four deaths have been attributed at least partially to flooding in central Pennsylvania, where emergency workers had to rescue residents from their homes or swamped vehicles. A fifth person was reported missing.

Derry Township Police Chief Patrick O'Rourke said the body of a man in his 70s was recovered from a home Wednesday after his basement walls collapsed.

"We took a direct blow yesterday," O'Rourke told The Associated Press early Thursday. "You can't get from one side of the town to the other."

Lancaster County Emergency Management Director Randy Gockley said a motorist in Elizabeth Township, near Lititz, drowned inside a car early Thursday after a creek topped its banks. Rescuers reported between 3 and 4 feet of water covered the road, Gockley said.

A man was also swept away while trying to wade through rushing flood waters in Penn Township, Gockley said.

In Northern Lebanon Township, a motorist in a disabled vehicle was killed after being struck by another car after getting out to warn other drivers of the rising waters.

The state Capitol was closed Thursday as the Susquehanna River was forecast to eventually rise to 29 feet at Harrisburg, six feet above what is consider major flood stage. At the governor's mansion, First Lady Susan Corbett helped take furnishings from the first floor to higher levels while outside, sandbags were stacked in a bid to stave off expected rising water.

"We're really preparing for it (water) to be on the first floor" for the first time since Agnes, she said.

Officials in Harrisburg said they were evacuating 6,000 to 10,000 residents from low-lying areas of the city.

PennDOT closed hundreds of roads across the eastern half of the state, including a temporary closure of the Schuylkill Expressway in Philadelphia. A bridge spanning the Delaware River between New Hope and Lambertville, N.J., also was closed. Portions of Interstates 81 and 80 were also closed.

Early Thursday, Gov. Tom Corbett ordered state offices in Harrisburg, Reading and Scranton closed for the day, affecting about 25,000 nonessential employees.

"We don't want anybody to risk their lives trying to get to work," said Corbett spokesman Gary Miller.

Dangerous travel conditions prompted a large number of school and university closures in a broad swath of northeastern to central Pennsylvania and the Red Cross set up shelters to house displaced residents.

A woman plucked from her Hummelstown home by rescuers said she was glad to be alive after a harrowing ordeal. Donna MacLeod was afraid to leave her home when she was advised to evacuate Wednesday night, but called 911 Thursday morning after the first floor of her house was flooded by 3 feet of water.

"I'm heartsick," she told The Associated Press. "I know I lost two cars and everything that was in my basement and everything that was on the first floor. But I have my life and I have my dog so that's good."

Tony Higgins was one of four people to spend Wednesday night in a shelter in Cumberland County after a sheriff's deputy knocked on his door, telling him he should get away from the rapidly rising Yellow Breeches Creek, which had already sent more than an inch of water into his New Cumberland home.

"I'm not used to a cot because I've got a slipped disk, but these people have been great," Higgins said.

Scolforo reported from Hummelstown, Pa. Randy Pennell and Maryclaire Dale in Philadelphia, Peter Jackson in Harrisburg and Genaro C. Armas in State College contributed to this report.