But dozens of interviews with inmates and their families, defense lawyers, jail staff, union officials and lawmakers briefed on the response of officials at the Bureau of Prisons painted another picture, revealing an account of the crisis that not only contradicted what the bureau said, but suggested it was even worse than it had initially appeared.

The blackout, which lasted for a week, ended Feb. 3, when power was restored amid public outcry. A few days later, the Justice Department, which oversees the federal Bureau of Prisons, said that it was “committed to the safe and humane living and working conditions of all inmates and employees,” and that its internal watchdog, the Office of the Inspector General, would investigate the facility’s infrastructure and emergency response.

Mr. Quay did not respond to requests for comment.

The blackout crisis was just the latest episode in a long history of neglect and brutality at the jail, one that has been documented in previous Justice Department reports. Investigators over the years have issued findings that suggest the jail is among the worst in the federal system, determining at different times that prisoners have been beaten, raped or held in inhumane conditions.

“It’s my opinion,” a former warden at the jail, Cameron Lindsay, said in an interview, that over the last decade “the M.D.C. was one of the most troubled, if not the most troubled facility in the Bureau of Prisons.”

The M.D.C., one of the largest federal lockups in the country, houses more than 1,600 inmates, some of them linked to high-profile drug trafficking and terrorism cases, most charged with lesser crimes. It is largely a way station, where inmates spend relatively short periods awaiting trial or sentencing.