In what could become the biggest criminal justice news of the year, a plan has been announced to shut down the jail that has held and criminalized countless Black and Brown people in New York City over the course of the last 85 years.

New York Mayor Bill de Blasio has agreed on a plan to close Rikers Island, the city jail facility that sits in the East River, only a few dozen yards from the runways of LaGuardia Airport. The lockup has gained its most recent infamy in the Kalief Browder case, in which the Bronx teen was held there awaiting trial for three years on a robbery charge that was eventually dismissed. But the traumatic effect his stay there had on him ultimately led to his suicide.

De Blasio said the move is part of an effort to end mass incarceration in New York. Currently 10,000 inmates are housed at Rikers Island.

“It will take many years. It will take many tough decisions along the way, but it will happen,” said de Blasio at a Friday press conference. He explained that this is the first time since the jail opened in 1932 that the city’s official policy will be to close down. But while he emphasized the process, he says it will not happen overnight.

“This is going to take a lot of work. There’s no quick fix here and anyone who says there is a quick fix isn’t being honest.”

The new policy comes about a year after a commission created by the New York City Council began to study the feasibility of ending the facility’s run. The 97-page report, obtained by The New York Times, recommends moving inmates off Rikers Island and into other facilities throughout the city’s five boroughs and tearing down the structures. The city would spend $10.6 billion over the next decade to make the phase out complete.

But a shut down is also not guaranteed. Certain criteria must be in place if it is to happen. For example, de Blasio said the inmate population would have to decrease to about 5,000, halving its present number and also if the crime rate in New York remains low.

Indeed the city’s rate has declined to the lowest number in decades, according to the NYPD. There were 998 shootings in New York in 2016, a 12 percent drop from the year before and the first time the number dipped below 1,000 since the city has kept records. Using their CompStat system, police counted about 101,000 crimes, which was down 4 percent and the lowest since they started using it two decades ago.

Also, the city tweeted this week that the Rikers Island population went down 23 percent and the overall city jail population is down 18 percent.

But although crime is lower in New York, there is still a marked disparity when it comes to race in New York’s jails. A 2013 study showed that at any given time 57 percent of population in the custody of the New York Department of Corrections is Black, another 33 percent is Latino and 7 percent is White. 93 percent is male.

There is also at least some irony in the fact that the the jail is named after the family of Richard Riker, a racist New York judge who constantly violated the Fugitive Slave Act by sending free Blacks into slavery at the behest of slave kidnappers.

Rikers Island itself has long been seen as a symbol of the problems created by mass incarceration and its effect on communities of color, which has led for calls to shut it down for years.

“There was nothing rehabilitative about Rikers, nothing correctional,” Glenn E. Martin, president of JustLeadershipUSA and who himself had been held at Rikers Island told the Village Voice last year. “In fact, people in the position of authority were helping to facilitate that atmosphere.”

Although the amount of effort behind shutting Rikers Island down is heavy, other advocates of its closure are also applauding de Blasio’s announcement. Legal Aid Society attorney Seymour James described the jail to the New York Daily News as a “long scourge to this city besetting justice, perpetuating recidivism and destroying Black and Brown communities.”

“We join New Yorkers from every borough today flushed with many emotions that the dream of closing Rikers Island will finally become reality,” he said.

Madison J. Gray is Digital Managing Editor of Follow him on Twitter @madisonjgray.