Beneath the headquarters of America’s premier crime-fighting organization, one of the parking ramps has been condemned because corroded pieces of the ceiling were falling on cars.

Netting hangs on the Ninth Street facade to prevent broken concrete from hitting passersby 160 feet down on the sidewalk below. During a July fire drill, half of the building’s alarms didn’t go off.

For more than a decade, leaders at the Federal Bureau of Investigation have warned that the bureau needed to replace the J. Edgar Hoover Building, a concrete fortress designed as a symbol of strength that has instead come to serve as a lesson in government inaction.

“Where else in the city is there something like that? The answer is nowhere,” said Dan Tangherlini, a former administrator for the General Services Administration, which oversees federal real estate. “In the private sector you would never do this. You would just fix it up.”

Three years ago, the federal government launched a search for a new site for its headquarters but that effort is months behind schedule. FBI officials fear that with Congress increasingly unwilling to pass funding measures, the move to a new building could be dramatically pushed back or set aside following next year’s election.

[GSA proposes trading Hoover Building for new FBI campus]

In the meantime, the FBI headquarters is crumbling. On a rare tour of the building, bureau officials pointed to cracked concrete, makeshift work stations in former storage areas and badly dated building systems. The officials said the structure is now so inefficient that it has begun to hinder the agency’s modern mission, one increasingly focused on combating international terrorist threats and cyber crime.

They are also increasingly concerned that the Hoover Building could be susceptible to attacks.

“Having a state-of-the-art facility that meets that mission is paramount,” said Richard L. Haley II, FBI assistant director and chief financial officer. “Security concerns are important. And you just have to open up the public records to see where you know bad things can happen if you don’t have the right security precautions.”

The Hoover Building’s decline has become a highly prominent example on Pennsylvania Avenue of the failure of Congress and the federal government to solve even straightforward real estate problems such as disposing of underused buildings or moving agencies to more efficient spaces.

Members of Congress have resisted supplying funds for construction of new buildings. The president’s budget officials have stuck to rigid spending rules that prevent the quick leasing of new space for the FBI.

The GSA proposed a building swap that could save $500 million — a laborious but cost-saving strategy similar to ones the agency has pursued in Boston, Denver and other locations across the country.

Looming over the process is the failed attempt to consolidate the Department of Homeland Security, whose own headquarters consolidation in Southeast D.C. won approval six years ago but is less than one-quarter complete, a decade behind schedule and more than $1 billion over budget.

Nearly three years after the FBI’s search began a final location has not been identified and funding has not been secured. In the meantime, the FBI’s 9,500 headquarters employees are spread throughout 14 locations in the Washington region.