Misplacing a house key is one thing.

Misplacing a Key house is quite another.

But apparently that's what the National Park Service has done with the home of Francis Scott Key, formerly of 3518 M St. NW.

"Whoops, I was afraid this was going to come up one of these years," said George Berklacy, the Park Service's public affairs director.

This bureaucratic imbroglio began in 1931, when the Park Service purchased the property along with an entire block of M Street homes. It was from this two-story, red brick house, in 1814, that Key set out for Baltimore to observe the rocket's red glare at Ft. McHenry, where he scribbled on the back of an envelope the lyrics to "The Star-Spangled Banner."

In 1947, in order to make room for the extension of K Street known as the Whitehurst Freeway, the Park Service was charged with dismantling Key's Georgetown residence, which so proudly was hailed as a historic landmark.

The disassembly of the house was done by Alexander and Repass, an Iowa construction firm that had won the contract to build the elevated highway. By the dawn's early light, and on through several weeks, workmen carefully made diagrams and photographs, numbered the parts, tore the building down and moved the pieces to the park area on the southeast corner where Key Bridge intersects with M Street -- which in Key's day was called Bridge Street. Park Service plans called for eventual reconstruction when a suitable site was found.

"I remember all those remains piled up there," recalled Robert C. Horne, 71, who was the Park Service's chief of engineering through the perilous fight. "I remember that mowing machines would circle all around the pile."

Eventually the pieces had to be moved, so they were placed in marked crates, according to Stanley McClure, a 75-year-old Park Service historian who has retired to a 176-acre farm near New Haven, Ohio. The materials were "stored away in some of our bins around town under bridges -- maybe it was the Arlington Memorial Bridge." The Historic American Buildings Survey records that the house was "dismantled in 1947 to make way for elevated expressway," notes that copious diagrams had been made to document the building's design, but doesn't mention the storage location of the dismantled parts.

So far so good.

Except that references began cropping up about the destroyed Key House. James Goode, in his seminal work for The Smithsonian, "Capital Losses," notes that the building was "razed." And dozens of Washington newspaper articles written since the construction of the Whitehurst Freeway state simply that the building was destroyed.

"What happened then wouldn't have happened today because of all the commissions," said Berklacy. "It would have taken 10 years to get the permits to move the thing, and in that time hopefully somebody would have made some records."

Several years later, the Park Service began restoring The Old Stone House, which stands on M Street between 30th and 31st in Georgetown.

"If my memory serves me correctly, that was '56, '57, somewhere in that area," said Joe Ronsivalle, the Park Service's land officer. "I'm fairly certain that some of the bricks went into the [Old Stone House] fireplace, and some of the boards went into the floor."

There was no proof last night that his home was still there.

"We have records through 1954, and that's apparently it," Berklacy said yesterday. "And who knows what's in those things."

"The Office of Design and Construction was theoretically responsible for all that, but there are no real records that I could find," said Agnes Downey Mills, the first curator of The Old Stone House, and now the Park Service's curator at Arlington House. "A lot of people felt bitter because they thought the Key house would be taken care of and it wasn't.

"There's probably a better chance of finding the physical pieces under some bridge than finding any records on it."

Oh say can you see, and then you can't.