Federal prosecutors in Manhattan said the authority, which houses at least 400,000 poor and working-class residents, covered up its actions, training its staff on how to mislead federal inspectors and presenting false reports to the government and public about its compliance with lead-paint regulations.

The failures endangered tenants and workers for years, the prosecutors said, and potentially left more children than previously known poisoned by lead paint in their apartments.

The accusations were contained in an 80-page civil complaint filed against the authority on Monday in federal court by the office of Geoffrey S. Berman, the U.S. attorney in Manhattan, after a lengthy investigation.

The problems at the authority “reflect management dysfunction and organizational failure,” the prosecutors said, “including a culture where spin is often rewarded and accountability often does not exist.”

Mayor Bill de Blasio said the public housing authority, known as NYCHA, chose to settle rather than face a trial, a decision that the city and housing experts said appeared to mark a nadir in a decadeslong history of disinvestment in New York City’s public housing, once seen as the rare national success story.

While cities like Chicago and St. Louis dynamited some of their most troubled projects, New York City held on. In some of the most rapidly gentrifying corners of the city, public housing apartments were islands of affordability.

But their chronic problems — from lead paint to unreliable heat in the winter — were also increasingly apparent. Politicians like Gov. Andrew Cuomo, a former federal housing secretary, and Scott M. Stringer, the city’s comptroller, toured developments and publicly lamented the poor conditions, including mold, roach infestations and labyrinthine rat burrows.

In signing an accompanying consent decree that is effective for a minimum of five years, NYCHA admitted to the conduct, and as part of a settlement, the city agreed to spend an additional $1 billion on the authority over the next four years, and $200 million per year after that.

NYCHA will also submit to oversight by a court-appointed monitor, and at a news conference Monday, Berman called the settlement “the beginning of the end of this nightmare.”

This article originally appeared in The New York Times.

BENJAMIN WEISER and J. DAVID GOODMAN © 2018 The New York Times