The Navy Annex was never intended to last long or, for that matter, to house human beings. The 1 million-square-foot complex, perched on an Arlington County hill overlooking the Pentagon, was designed as a temporary warehouse but pressed by wartime needs into service as offices for the Navy and Marine Corps.

Seven decades later, including more than 50 years as Marine Corps headquarters, the Navy Annex is coming down. Demolition crews are gutting the interior and, late last month, began tearing down the complex’s exterior walls. The 42-acre site is to be turned over to neighboring Arlington National Cemetery for grave sites.

The demise of the Navy Annex, built quickly in 1941 on the eve of U.S. entry into World War II, sheds light on a curious subspecies of Washington area structures: the temporary government office building.

“The old joke is there’s nothing in Washington as permanent as a temporary building,” said G. Martin Moeller Jr., senior curator at the National Building Museum.

Even by Washington temporary standards, the annex had a long life. The infamous Munitions and Main Navy buildings, enormous and ugly industrial-style buildings constructed during World War I on the Mall between the Lincoln Memorial and Washington Monument, were supposed to be torn down when the Great War ended but instead were not demolished until the Nixon administration. They lasted a little over 50 years, two decades less than the Navy Annex.

A map locating the Navy Annex in Arlington County, Virginia. (Laris Karklis/The Washington Post/-)

It will take awhile to tear down the annex on Columbia Pike, with its seven four-story comblike wings that were home to 6,000 workers in its heyday. An eighth wing was torn down in 2004 to make way for the Air Force Memorial.

“It was built to last, even though it was built to be temporary,” said Kevin Mahoney, the project manager for the ­Corinthian-DSI joint venture that was awarded a $10 million contract in August to demolish every trace of the annex and restore the grounds to green space by September.

A building of many uses

At a low-key demolition ceremony held recently at the annex’s main entrance, William Brazis, director of the Pentagon’s Washington Headquarters Service, which oversees the Navy Annex, paraphrased Ecclesiastes 3:3. “There’s a time to build, and a time to tear down,” he said, “and it is time to start tearing this building down.”

Not many tears were shed. “No one would tell you it was the most architecturally pleasing place,” Brazis said. “It was thrown up like a warehouse, and it showed.” Even its second official name — Federal Office Building 2, or FOB 2 — was inelegant.

Though perhaps never loved, the building proved quite useful over the years.

“There’s a tendency to underestimate the reluctance to tear down a temporary building,” Moeller said, “not because of any love for it, but because it’s there.”

Military headquarters in Washington were bursting at the seams during the buildup to World War II. The Arlington annex was part of an explosion of construction that also included the Pentagon, built by the War Department to house the Army headquarters.

On Nov. 8, 1941, the Marine Corps moved its headquarters from the temporary Main Navy building, where it had been for more than two decades, and into the new annex. One month later, after the Japanese attacked Pearl Harbor, the annex became the rear command post from which the Corps directed Marines through the Pacific, from Guadalcanal to Iwo Jima.

After the war, even when President Harry Truman ordered the Navy to move its headquarters into the Pentagon in 1948, the Marine Corps stayed in the Navy Annex until 1996, preferring the independence.

The annex also housed a variety of Navy offices and eventually became home to the Missile Defense Agency. When the Sept. 11, 2001, attack destroyed the Navy Command Center at the Pentagon, it was reconstituted at the annex.

The annex never underwent major renovation, other than a $3.25 million spruce-up in the 1970s that included a new roof, carpeting and replacement of the World War II-era wiring. The windows were painted over so many times that many did not close, leading to regular complaints of freezing temperatures.

Some viewed assignment to the spartan building as a form of exile. “That’s how you knew you were a bad person,” said Michael Dangerfield, who did temporary duty at the annex while in the Army and is now the Defense Department program manager for the demolition. “They sent you to the Navy Annex. They didn’t send you to Rosslyn or Crystal City.”

Legislation passed in 2000 by Congress directed that the demolition be completed and the land turned over to the cemetery nearly three years ago. But the annex proved so useful as swing space for workers dislocated by the 2005 base closures and the Pentagon renovation that the Defense Department received a series of one-year extensions.

Occupants dismissed warnings to vacate by the end of 2011.

Dangerfield installed a countdown clock, but no one paid attention.

“People were laughing at us,” said Dangerfield, who responded by cutting off food service.

“That’s when they took us seriously,” he said.

Removing the ATM helped, too.

Now the Navy has carted away the World War II-era anchors and ship bells that provided decorative touches. At the entrance, a hole in the brick facade is all that is left where the Marine Corps plaque was chiseled out. Concrete mold eagles remain above another entrance, looking forlorn. They have proved impossible to remove and will be crushed into dust.

Remains of the day

Inside, windows have been smashed, holes knocked through walls and doors blown off their hinges. It is not the work of the demolition crews. For much of the past year, the annex hosted training exercises for police SWAT teams, FBI and Secret Service agents, and firefighters. Officers roamed corridors firing paintballs and beanbags at one another, setting off controlled explosions and running police dogs through the building.

A huge panoramic glass entry to the Missile Defense Agency was blown to smithereens.

“There wasn’t a piece of glass that the police didn’t like blowing up,” Dangerfield said.

The last SWAT teams have been evicted, and the annex is the domain of 85 demolition workers, some of them mindful of the history they are dismantling. Mahoney’s grandmother worked at the annex during the war, typing letters to the families of deceased troops.

Hints of that history are scattered about, including abandoned wall placards and the wood wainscot in the corridor leading to the Marine commandant’s office.

On the fourth floor, an enormous, V-shaped wood-laminated table that once hosted top-secret video conferences was abandoned by the Missile Defense Agency.

“This conference table — everybody in the world wants it,” Dangerfield said. But no one wanted to pay $1,500 to restore power for the elevator needed to remove the table.

In sealed-off areas, workers in protective suits are stripping asbestos-laden material and packing it in boxes for shipment to a toxic-waste facility.

Crews gutting the insides have pushed debris out of openings to the ground outside, where a 30-ton excavator sorts huge piles of brickwork, trash and metal. Truckloads of material depart every day to be recycled or dumped.

Some see the Navy Annex’s future as a cemetery as appropriate.

“It’s fitting as a resting place for those who served the nation,” Brazis said.