A million New York school children returned to classes Monday a week after superstorm Sandy devastated much of the U.S. East Coast, but workers endured long commutes to their jobs and 1.4 million people remained without power.

Even as the city struggled to regain some semblance of a normal start to the work week, thousands of New York and New Jersey residents remained homeless. Their homes were left uninhabitable by the storm's raging flood waters or destroyed by wind-swept fires.

New York Mayor Michael Bloomberg estimated that the storm left 30,000 to 40,000 homes uninhabitable. Authorities are particularly concerned about the plight of the homeless as night-time temperatures in the eastern U.S. are now falling to near freezing.

Bloomberg joined work commuters Monday morning, taking a subway to his office. The city's transit authority said about 80 percent of its trains are now back in service, but one major rail link across the Hudson River into the city from New Jersey remained shut.

About 90 percent of the city's 1,700 schools reopened. But about 100 were still closed because of the storm damage they sustained or are being used as emergency shelters.

Some residents in the storm's path sought to recover what little they could of their belongings and family mementos. But one survivor, Betty Duffy, said almost all of her possessions were lost.

“Most of us left here with what we had on, maybe one other outfit, and now we come back and we have no clothing, no nothing.''

U.S. Homeland Security Secretary Janet Napolitano says the federal government is looking to move the homeless from shelters to temporary apartments and hotels.

Napolitano said Sunday that inspectors from the Federal Emergency Management Agency are trying to assess the needs of the thousands of people displaced by the storm.

The storm killed more than 100 people and caused up to $50 billion in damages.