Banging heard outside the Metropolitan Detention Center in Brooklyn on Friday night was a desperate cry for help from detainees seeking relief from the bone-chilling cold temperatures inside their cells.

Rhonda Barnwell, whom works in the detention center, said the waterfront facility is a virtual icebox for employees and inmates.

"They're complaining about heat as well, they can't speak, their throats are hurting," Barnwell told members of the media.

Since Sunday, small reading lights, which they used Friday to bang on their cell windows, are all that illuminates their cells. The city fire department said a small electrical fire plunged the federal lockup into darkness that day, sparking fear among those in the building.

"We have dark spots where we're moving inmates and there is no light, so we're really afraid for the staff members' safety, as well as the inmates. Because there's a lot of places where we cannot see," Barnwell said. "Some of the officers got injured today trying to lock the inmates back in their cells."

The problems didn't start with that electrical fire, though. Employees told New York Rep. Nydia Velazquez, during her tour of the facility Friday, that the place has been without heat since January 21.

"They have to work with their coats, their gloves, covering their heads," Velazquez said. "The cold weather, the temperature, was unbearable."

NY1 first reported, two weeks ago, that the detention facility was experiencing staffing shortages, forcing the warden to shut down attorney and family visits for an entire week.

"It's important to realize that these are people who are pre-trial detainees. They haven't been convicted of crimes," said David Patton, the chief federal defender for New York. "They're entitled to have daily access to their attorneys."

A woman whose husband is an inmate at the jail said she's been calling every day and can't get in touch with him. She asked us to disguise her identity for fear of retribution by the staff.

"I was told that the facility was on lockdown. I called back again on Tuesday to find what was going on and they had no information to give me. I decided to drive down to the facility and all of the lights are shut off," she said.

The Federal Bureau of Prisons told NY1 that the cells have heat and hot water. But attorneys don't buy that.

"The warden, Herman Quay, at the MDC, either doesn't know what happening at his institution, or he's not being honest about what's happening at his institution because the conditions are not acceptable," Patton said.

The Federal Defenders of New York have filed an emergency motion for bail for many of their clients. They're hoping they are pulled out of Metropolitan Detention Center and are assigned to home confinement so they have a place that is warm.