By: Trey Bundy, The Center for Investigative Reporting

NEW YORK — There’s not much inside “the box.” Cinder block walls rise up and close in. There’s a bunk, a sink, a toilet and a metal door with a small mesh window. Food comes through a slot. Sometimes, mice and roaches scamper through.

Teenagers kept in the box sometimes hallucinate and throw fits. They splash urine around or smear their blood and shit on the walls. The concrete room gets so hot in the summertime that the floor and walls sweat.

Ismael Nazario’s longest stretch in the box lasted four months. He paced a lot, talking to himself and choking back tears and rage. He tried to block out the screaming of the teenage boys in other jail cells in his unit, but he couldn’t. Sometimes, he would stand at the door of his tiny cell and yell.

“You just get angry with hearing people constantly hollering all day,” he says. “There’s so many people that have been in that cell and screamed on that same gate, it smells like a bunch of breath and drool.”

Nazario is one of hundreds of teenagers sent in recent years to solitary confinement at Rikers Island, the massive jail complex in the middle of New York City’s East River. Teenagers at Rikers call solitary confinement the box: 23 hours a day in a 6-by-8-foot cell. (See related video.)

“There came a time when I cried when I was on Rikers Island, in the box, when I was there by myself,” Nazario says. “There’s times, you know, sometimes you need a good cry.”

Because of its imposing size and notoriety, many people think Rikers is a prison, but it’s not. It’s a city jail, where on any given day about 85 percent of inmates await the resolution of their cases, according to the New York City Board of Correction. Most of the teenagers there are locked up because they can’t afford bail.

In New York, anyone who is 16 or older is considered an adult under state criminal law. Rikers, one of the largest jails in the world, has an adolescent population that can rival the biggest adult jail systems in the country: between 400 and 800 a day.

Solitary confinement at Rikers is officially called punitive segregation. Officials say the practice is reserved for the most dangerous inmates. But Rikers’ rules say 16- and 17-year-olds can be sent to the box for horseplay and “noisy behavior” or if they “annoy” staff members. Teenagers with “unauthorized amounts” of clothing or art supplies can go to solitary, too.

At any given time, about 100 teenagers are housed in solitary confinement at Rikers Island — an abnormally high number compared with estimated rates of solitary confinement across the U.S.

Nazario first went to Rikers at 16, after an arrest on an assault charge. Before leaving at 19, he says, he had spent more than 300 days in solitary confinement — all before being convicted of a crime.

Every day, thousands of teenagers around the U.S. are held in solitary confinement, but no one knows for sure how many. That’s because the federal government does not require prisons, jails and juvenile halls to report the number of young people they put in isolation or how long they keep them there. After months of requests, officials at Rikers Island have yet to provide information on their facility. They declined to give interviews and denied requests for a tour of the solitary units. An October email to The Center for Investigative Reporting from spokesman Eldin Villafane reads: “I have to make clear to you at this point that the Dept of Correction will not be participating on your piece. Please discontinue your requests.”

Last month, New York state prison officials said they would ban the use of solitary confinement as punishment for minors. But that settlement, forged after a lawsuit by the New York Civil Liberties Union, does not apply to Rikers jail, which is run by the city of New York.

Despite the movement in New York, the U.S. has failed to significantly address the issue of holding minors in solitary confinement. Most state laws are vague or nonexistent. Prisons, jails and juvenile halls try to keep their records secret and refuse to open their doors to scrutiny, and the federal government allows states to operate with little oversight. Along the way, the stories of minors locked up alone for months persist, despite strong evidence that extended periods of solitary confinement can lead to mental illness and suicide.

In Polk County, Fla., where juveniles are held in adult jail, Sheriff Grady Judd is being sued for locking teenagers in isolation cells for months on end. Those at risk of committing suicide were dressed in smocks and held in cages, usually alone but in full view of other inmates, the suit says. In New Jersey, the state’s Juvenile Justice Commission settled a civil rights lawsuit in January for $400,000 after keeping a teenage boy in isolation for 178 out of 225 days, even though he was severely mentally ill. In Texas, state records show that in 2012, juvenile facilities locked minors in solitary confinement more than 36,000 times.

Every state has its own system for collecting data, if it collects any at all, and each defines solitary confinement in its own way. Obscuring the picture further, states including Texas and California allow juvenile facilities to create their own isolation policies, and their numbers can go unreported.

For example: In 2011, an audit of California’s Division of Juvenile Justice found 249 instances of inmates being locked in their cells for 22 to 24 hours a day, a violation of the agency’s own policy. The auditors found that those numbers — from four youth prisons over four months — had not been reported to state headquarters and that agency officials had failed to monitor conditions inside the facilities.

If tracking juvenile isolation is tough, regulating it is tougher.

The U.S. Department of Justice has called prolonged juvenile isolation cruel and unusual punishment. Attorney General Eric Holder has condemned the practice, and U.S. Sen. Dick Durbin, D-Ill., has convened congressional hearings on solitary confinement. Despite increasing rhetoric in Washington, no federal laws prohibit solitary confinement for youth or limit the number of weeks or months they can be locked in their cells for 23 hours a day.