(CNN) -- States up and down the East Coast are bracing for Hurricane Sandy, which could make landfall anywhere between Maryland and Pennsylvania, according to the latest forecast map from the National Hurricane Center.
Here's a look at how coastal states are rushing to prepare for potentially devastating effects:
Bus service in Connecticut will stay closed for the duration of the storm, Gov. Dan Malloy announced Sunday.
"Folks, this could be bad -- really bad," Malloy said, noting that forecasters are predicting 36 hours of sustained winds. "It could impact us in several ways and for a long period of time. Please take this as seriously as we are taking it."
Malloy said his state will have 400 National Guard troops ready to assist with recovery efforts as needed.
President Barack Obama has declared a state of emergency for Connecticut.
Even before the center of Sandy ran aground, parts of the Delaware coast were already experiencing significant flooding.
"We're seeing more flooding than you normally do, and particularly since the storm's not here," Gov. Jack Markell said Sunday.
Earlier, the governor declared a "limited" state of emergency, meaning it doesn't order driving bans or business closures.
Markell ordered the evacuation of all coastal communities and a flood-prone area in southern Delaware.
Shelters opened beginning Sunday afternoon to accommodate those who have left their homes but have nowhere else to go, Markell said.
DISTRICT OF COLUMBIA
The city's mass transit system, known as the Metro, will stay idle on Monday.
All of Washington's public schools will be closed Monday, Mayor Vincent Gray announced. "The district is preparing in earnest" for the storm's effects, which could include heavy rain, street flooding, strong winds, power outages, and storm-surge flooding along the Potomac River and its tributaries, Gray said.
All federal buildings in the district will be closed to the public Monday.
Obama declared a state of emergency in the District of Columbia on Sunday.
The Maine Emergency Management Agency warned Sandy could create "significant problems" in the state, such as high surf, fierce winds and coastal erosion.
In anticipation of widespread power outages, Gov. Paul LePage signed a "limited emergency declaration" so power crews from other states and Canada can help the state prepare for Sandy. The declaration also extends the hours that power company crews can drive.
Gov. Deval Patrick declared a state of emergency for the Bay State.
Hoping to avoid the kind of criticism utilities received after last year's Hurricane Irene and other storms, Patrick said utilities plan to pair tree removal and power restoration crews -- rather than having them work separately -- so that work can be done more efficiently.
The city of Boston announced that schools will be closed Monday.
Obama also declared a state of emergency for Massachusetts.
Like several neighboring states, Maryland could see as much as a foot of rain in some areas -- a major reason the state has declared a state of emergency.
Besides flooding, strong winds are expected to cause significant power outages. The Baltimore Gas and Electric Company, for instance, says several hundred thousand customers could be affected.
Public schools in Baltimore, Montgomery and Prince George's County will be closed Monday.
In the coastal city of Annapolis, city crews distributed sandbags to residents and businesses to help them prepare for flooding.
President Obama declared a state of emergency in Maryland on Sunday.
Sandy could bring winds of up to 60 mph and dump 2 and 4 inches of rain to parts of the Granite State -- likely starting Monday, Gov. John Lynch's office said.
"While the exact path and severity of the storm remain uncertain, it is clear New Hampshire will experience a significant weather event and I urge everyone to be prepared," Lynch said.
New Jersey was the first to announce mandatory evacuations. The state's barrier islands from Sandy Hook south to Cape May must be cleared out, along with Atlantic City's casinos.
"We have to prepare for the worst here," Gov. Chris Christie said. Tolls have been suspended on the northbound Garden State Parkway and the westbound Atlantic City Expressway so people in those areas can leave more quickly, he said.
All state offices will be closed on Monday, with only essential employees expected to report to work, Christie announced.
New Jersey Transit came to a halt and will remain suspended indefinitely.
New York City's ubiquitous public transit system shut down ahead of Sandy's landfall, leaving iconic sites such as Grand Central Terminal and Penn Station empty.
The city expects a slow surge of water to flood low-lying areas such as Queens, the Bronx and Battery Park in Manhattan, Mayor Michael Bloomberg said.
Mandatory evacuations are in place for parts of New York City. Evacuation centers have been opened in 76 locations, and schools in the city are closed Monday.
Offices at United Nations headquarters in Manhattan also will be closed Monday, as will the physical trading floor of the New York Stock Exchange. Operations will continue on the company's electronic exchange.
The Broadway League canceled all Broadway performances Monday night, citing the suspension of public transportation.
Instead of tourists and theater fans, piles of sandbags lined Broadway.
Gov. Andrew Cuomo directed Army and Air National Guard members to mobilize for Sandy, and Obama has declared a state of emergency for New York.
Strong winds and rain that fell sideways lashed the Outer Banks as the outskirts of Sandy pummeled the barrier islands.
Forecast expect between 4 and 7 inches of rain to fall over several days in the Outer Banks, with some spots receiving 8 or more inches.
Gov. Tom Corbett declared a statewide disaster emergency ahead of the storm, Corbett's office said.
Flooding, power outages and sustained high winds are anticipated, his office said. Sandy could even bring snow to parts of southwestern Pennsylvania and in higher elevations.
"Essentially, this is a hurricane wrapped in a nor'easter," Corbett said.
Public schools in Philadelphia will be closed on Monday.
Public transportation in the Philadelphia area has been suspended.
The Rhode Island Emergency Management Agency urged all residents to prepare for prolonged power outages, wind damage and water damage by keeping an emergency kit, securing property and taking boats out of the water.
State authorities have taken precautions such as checking and clearing drains in flood-prone areas and relocating state equipment if necessary.
Public schools in Providence, the state capital, will be closed Monday.
Obama has declared a state of emergency for Rhode Island.
Radar showed heavy rains from the fringes of Sandy pelting much of South Carolina's coast, from Charleston to Myrtle Beach.
The Palmetto State is expected to avoid a direct hit from the storm, which is expected to make landfall well to the north.
Virginia was one of several states to declare a state of emergency ahead of the storm. Computer models predict parts of the state could see as much as a foot of rain.
Sandbags piled up inside restaurants in the Old Town section of Alexandria, along the banks of the Potomac River.
The Virginia National Guard was authorized to bring as many as 500 personnel onto active duty.
All public schools in Fairfax County, a large school district in northern Virginia, will be closed Monday and Tuesday. Schools in Arlington, Norfolk, and Newport will be closed on Monday.
CNN's George Howell, Athena Jones, Greg Botelho and Melissa Gray contributed to this report.