Free but limited bus service was resumed Tuesday evening to take up some of the slack left behind by the crippled subway system, and the New York Stock Exchange was scheduled to resume trading Wednesday morning.
While the East Coast was still grappling with the scope of the disaster, federal officials warned that Sandy was an ongoing concern with the potential to inflict more pain on inland states. The storm was centered about 50 miles east of Pittsburgh and packing 45-mph winds Tuesday evening, bringing flood warnings to Michigan, Ohio and Pennsylvania and blizzard warnings to higher elevations in the Appalachian Mountains.
"The coastal impacts are certainly less today than they were last night, but the effects are not zero," National Hurricane Center Director Rick Knabb told reporters in a conference call.
Forecasters predict the storm's center of circulation will be north of the Great Lakes by Wednesday. But coastal flooding in the 2- to 4-foot range could still occur "in spots," while the potential for other floods stretched as far west as Lake Michigan, Knabb said.
The full scale of Sandy's wrath has yet to be determined. But according to a government prediction, the storm's wind damage alone could result in more than $7 billion. One estimate from Kinetic Analysis Corp., which conducts weather hazard assessments, said the storm's economic impact could be up to $25 billion.
In Washington, President Barack Obama pledged the full support of the federal government for recovery efforts. He signed major disaster declarations for New Jersey and New York on Tuesday, clearing the way for federal aid to residents and to state and local authorities.
"My instructions to the federal agency has been, 'Do not figure out why we can't do something. I want you to figure out how we do something. I want you to cut through red tape. I want you to cut through bureaucracy.' There's no excuse for inaction at this point," Obama said during a visit to the headquarters of the American Red Cross. "I want every agency to lean forward and to make sure that we are getting the resources where they need -- where they're needed as quickly as possible."
The storm's timing a week before the presidential election is tricky for Obama and Republican challenger Mitt Romney. Both candidates sought to balance the real threat of a killer storm against the need to squeeze out any last-minute advantages in battleground states ahead of next Tuesday's vote.
Obama discarded campaign events in Florida and Virginia to return to Washington and address the storm from the White House. He was scheduled to travel to New Jersey on Wednesday and survey storm damage, the White House said.
On Tuesday, Romney swapped campaign rallies for a relief event in Ohio.
"We have heavy hearts as you know with all the suffering going on in a major part of our country. A lot of people are hurting this morning," said Romney, adding that he had the chance to speak with some of the governors from the affected areas.