WILKES-BARRE, Pa. ? Up to 200,000 people in the Wilkes-Barre area were ordered to evacuate their homes Wednesday because of rising water on the Susquehanna River, swelled by a record-breaking deluge that has killed at least 12 people across the Northeast.

Thousands more were ordered to leave their homes in New Jersey, New York and Maryland. Rescue helicopters plucked residents from rooftops as rivers and streams surged over their banks, washed out roads and bridges, and cut off villages in some of the worst flooding in the region in decades, with more rain in the forecast for the rest of the week.

Wilkes-Barre, a city of 43,000 in northeastern Pennsylvania coal-mining country, was devastated by deadly flooding in 1972 from the remnants of Hurricane Agnes. It is protected by levees, and officials said the Susquehanna was expected to crest today just a few feet from the tops of the 41-foot floodwalls.

An estimated 150,000 to 200,000 people in the county of about 351,000 were told to get out by nightfall. The evacuation order applied to more than half the residents of Wilkes-Barre, as well residents of several outlying towns, all of them flooded by Agnes more than three decades ago.

A dozen helicopters from the Pennsylvania National Guard, the state police and the Coast Guard were sent on search-and-rescue missions, plucking stranded residents from rooftops in Bloomsburg, Sayre and New Milford. Hundreds of National Guardsmen prepared to distribute ice, water and meals ready to eat. Flooding closed many roads in the Philadelphia area, including the Pennsylvania Turnpike.

The Susquehanna River threatens the Market Street Bridge in Wilkes-Barre, Pa. More than 200,000 people in the city and outlying towns were ordered to evacuate Wednesday.

An estimated 2,200 people were ordered to evacuate the area around Lake Needwood at Rockville, Md., which was approaching 25 feet above normal. Engineers reported weakened spots on the lake’s earthen dam.

A swollen creek carved a 25-foot-deep chasm through all four lanes of Interstate 88, about 35 miles northeast of Binghamton, and two truckers were killed early Wednesday when their rigs plunged into the gaps, officials said.

The soaking weather was produced by a low-pressure system that has been stalled just offshore since the weekend and pumped moist tropical air northward along the East Coast.

A record 4.05 inches of rain fell Tuesday at Binghamton, N.Y. During the weekend, the same system drenched the Washington and Baltimore region with more than a foot of rain.

Although the bulk of the rain moved out of the area Wednesday, streams were still rising from the runoff, and forecasters said more showers and occasional thunderstorms were possible along the East Coast for the rest of the week.