Now it was surely worse: That morning, it had been 2 degrees.

Ms. Ginsberg, the lawyer, told me to email Deirdre von Dornum, the lead public defender at the federal defenders office in Brooklyn, which represents hundreds of indigent inmates at the jail.

She sounded almost as if she had been expecting me.

Calls had been pouring in from the jail, Ms. von Dornum said. A phone line that connects the holding facility to the federal defenders was working, and when inmates were briefly released from their cells, they rushed to the phone.

As the temperature dropped, the inmates’ calls increased. “They sound really frightened,” she said.

Ms. von Dornum’s office had beseeched the warden for answers, but had received only curt replies, like, “legal visiting will be suspended.”

By the end of the day I had talked to several federal defenders and paralegals, gathering the accounts of about three dozen inmates.

Leaders of the correction officers’ union corroborated the inmates’ accounts of conditions at the jail. I called the M.D.C. and wrote — repeatedly — to the warden and his staff, who work for the federal Bureau of Prisons.

The next morning, Feb. 1, we published a story that described in detail the darkened world inside the jail.

By later that day, news trucks were there. The local congresswoman, Nydia Velázquez, arrived. Ms. von Dornum secured a court order to go inside and check on the inmates.