Feds sue New York City over widespread violence against young inmates at Rikers Island jail

New York City Mayor Bill de Blasio is joined by, from left, Department Correction Commissioner Joe Ponte and Warden Becky Scott during his tour of Second Chance Housing at Rikers Island jail facility on Wednesday, Dec. 17, 2014 in New York. The facility serves as alternative housing for incarcerated adolescents. De Blasio announced the city has ended its longstanding practice of sending 16- and 17-year-old inmates to solitary confinement for breaking rules. (AP Photo/The Daily News, Susan Watts, Pool) (The Associated Press)

FILE - This June 20, 2014, file photo, shows New York's biggest lockup, Riker's Island jail. Federal prosecutors sued New York City on Thursday, Dec. 18, 2014, to speed the pace of reforms at the Rikers Island jail complex and address what a Justice Department investigation found was a "deep-seated culture of violence" against young inmates. (AP Photo/Seth Wenig, File) (The Associated Press)

FILE - This June 20, 2014, file photo, shows the Rikers Island jail complex with the New York skyline in the background. Federal prosecutors sued New York City on Thursday, Dec. 18, 2014, to speed the pace of reforms at Rikers and address what a Justice Department investigation found was a "deep-seated culture of violence" against young inmates. (AP Photo/Seth Wenig, File) (The Associated Press)

Federal prosecutors have sued New York City to speed reforms at the troubled Rikers Island jail complex.

The lawsuit was filed Thursday to address what a Justice Department investigation found was a culture of violence against young inmates.

It comes one day after Mayor Bill de Blasio visited Rikers to announce the end of solitary confinement for 16- and 17-year-old inmates. The end of solitary was just one of 73 recommendations made by federal prosecutors to curb the violence.

In court papers, Attorney General Eric Holder and Manhattan U.S. Attorney Preet Bharara (buh-RAH'-ruh) wrote that despite four months of negotiations with the city, federal prosecutors "have been unable to reach agreement as to lasting, verifiable and enforceable reforms."

Emails seeking comment from the mayor's office and city lawyers weren't immediately returned.