Hillary Rodham Clinton, exploring the New Jersey lab where Thomas Edison invented many modern conveniences, said Tuesday there are endangered historical sites in every community that are worth saving.

"Some places can kind of hobble along" without major expenditures while "others are literally falling apart and may have to be condemned," she said on NBC's "Today" show. "The good news is that Americans have a great interest in our history and a lot of work is being done."The first lady is visiting several historical sites to call attention to the need to protect the nation's artifacts and records.

The Edison National Historic Site, inside a collection of red brick buildings, is less a museum than a repository for artifacts and papers documenting 44 years of Edison's work.

For years, the papers have been stored, uncataloged, in boxes throughout the facility - quite a casual arrangement for a man credited as the founder of modern American science, the holder of more patents than anyone in U.S. history.

"I was stunned," Hillary Clinton said Monday, noting that 400,000 artifacts, including prototypes of Edison's inventions, his lab notes and recordings - as well as 5 million pieces of paper - "were sitting, literally, in boxes that could be destroyed at the drop of a match or the strike of a lightning bolt."

The facility, where Edison developed alkaline batteries and the phonograph, became the responsibility of the National Park Service in 1956. But the service hardly has enough money to care for Edison's work, the first lady said, because it has a $1.2 billion maintenance backlog.

"The amount of responsibility we have put on the shoulders of the Park Service is something they cannot bear alone," the first lady said. "The rest of us, in the public and private and nonprofit sectors, have to help out."

Some of that help was expected from General Electric, the latest corporation to step up to the call for private investment for salvaging national treasures.

The Edison lab was the first stop of a busy day for the first lady. Her bus tour was proceeding to Newburgh, N.Y., headquarters of George Washington's Continental Army, before traveling to Massachusetts.