COLUMBIA (AP) — The Columbia Training School — pleasant on the outside, austere on the inside — has been home to 37 of the most troubled young women in Mississippi.

If some of those girls and their advocates are to be believed, it is also a cruel and frightening place.

The school has been sued twice in the past four years. One suit brought by the U.S. Justice Department, which the state settled in 2005, claimed detainees were thrown naked in to cells and forced to eat their own vomit. The second one, brought by eight girls last year, said they were subjected to ‘‘horrendous physical and sexual abuse.’’ Several of the detainees said they were shackled for 12 hours a day.

These are harsh and disturbing charges — and, in the end, they were among the reasons why state officials announced in February that they will close Columbia. But they aren’t uncommon.

Across the country, in state after state, child advocates have deplored the conditions under which young offenders are housed — conditions that include sexual and physical abuse and even deaths in restraints. The U.S. Justice Department has filed lawsuits against facilities in 11 states for supervision that is either abusive or harmfully lax and shoddy.

Still, a lack of oversight and nationally accepted standards of tracking abuse make it difficult to know exactly how many youngsters have been assaulted or neglected.

The Associated Press contacted each state agency that oversees juvenile correction centers and asked for information on the number of deaths as well as the number of allegations and confirmed cases of physical, sexual and emotional abuse by staff members since Jan. 1, 2004.

According to the survey, more than 13,000 claims of abuse were identified in juvenile correction centers around the country from 2004 through 2007 — a remarkable total, given that the total population of detainees was about 46,000 at the time the states were surveyed in 2007.

Just 1,343 of those claims of abuse identified by the AP were confirmed by various authorities. Of 1,140 claims of sexual abuse, 143 were confirmed by investigators.

Experts say only a fraction of the allegations are ever confirmed. These are some of the most troubled young people in the country and some will make up stories. But in other cases, the youth are pressured not to report abuse; often, no one believes them.

Undoubtedly, juvenile correction facilities and their programs benefit many of the youth who experience them by offering substance abuse programs, educational courses and mental health counseling. And for many troubled youth, the facilities are the last hope to straighten out problems that could eventually lead them to suicide, prison or other institutions.

Still, advocates for the detainees contend that abuse by guards remains a major problem and that authorities aren’t doing enough to address the situation.

In 2004, the U.S. Justice Department uncovered 2,821 allegations of sexual abuse by juvenile correction staffers. The government study included 194 private facilities, which likely accounts for the higher numbers than the AP found.

But some experts say the true number of sexual incidents is likely even higher. Some youth view sexual relationships with staff members as consensual, not as adults in positions of authority abusing their power.

Sue Burrell, an attorney for the Youth Law Center in San Francisco, recalls investigating sexual encounters between female staff and male inmates at a juvenile facility in Florida. ‘‘One of the boys I interviewed said he didn’t think it was fair that his roommate had a relationship with one of the staffers and he didn’t.’’

Other abuse is physical, and often sadistic.

For boys at the Hawaii Youth Correctional Facility, authority came in the person of 50-year-old Gilbert Hicks, and he wielded that authority emphatically.

Hicks was convicted of sexual assault in October 2005 after he ‘‘grabbed, squeezed and twisted’’ a boy’s testicles, according to a federal lawsuit.

When the boy sought medical attention 10 days later because of pain and swelling, Hicks, who had worked at the facility for 24 years, taunted him by asking: ‘‘What, you want me to squeeze your (genitals) again?’’

Hicks allegedly abused two other boys the same way.

His sentence? Five years probation and 90 days in jail to be served on weekends.

What sets the case apart from many others is the successful conviction. Often such cases come down to the word of a guard against that of a teenager with a long criminal record, the primary reason that so few charges of abuse are confirmed and prosecuted, child advocates say.

While it is likely that incarcerated youth make false allegations of mistreatment against their guards, there are cases of abuse not being reported because ‘‘many children are afraid of what would happen if they snitch on staff,’’ said Mark Soler, executive director of the Center for Children’s Law and Policy in Washington D.C.

The worst physical confrontations can end in death. At least five juveniles died after being forcibly placed in restraints in facilities run by state agencies or private facilities with government contracts since Jan. 1, 2004.

The use of restraint techniques and devices and their too-aggressive application have long been controversial and came under intense scrutiny last year after the death of 14-year-old Martin Lee Anderson.

A grainy video taken at a Florida boot camp in January 2006 shows several guards striking the teen while restraining him. Six guards and a nurse were acquitted Oct. 12 of manslaughter charges after defense attorneys argued that the guards used acceptable tactics.

In Maryland, 17-year-old Isaiah Simmons lost consciousness and died after he was held to the floor face down at a privately owned facility that was contracted by the state. Prosecutors say the staff waited 41 minutes after the boy was unresponsive to call for help.

Scott Rolle, an attorney for one of the counselors, had said the men were only trying to prevent Simmons from hurting himself or someone else.

A judge dismissed misdemeanor charges against five counselors; the state has appealed.

Other restraint-related deaths were three boys — 17, 15 and 13 — in facilities in Tennessee, New York and Georgia, respectively. At least 24 others in juvenile correction centers died since 2004 from suicide and natural causes or preexisting medical conditions.

Supervision does not have to be abusive to be problematic. The absence of supervision creates its own misery.

Advocates say sex among detainees is also a major problem in some facilities, a claim backed by government findings. A U.S. Department of Justice report described sex at the Plainfield Juvenile Correctional Facility in Indiana as ‘‘rampant.’’

And sometimes suicidal youth or those who want to harm themselves in other ways don’t get the personal attention they need.

Mississippi’s juvenile correction centers have been under the supervision of a court-appointed monitor since 2005 as part of the settlement to end the lawsuit filed by the federal government.

But a 15-year-old girl on suicide watch at Columbia Training School used a toe nail and the sharpened cap off a tube of toothpaste to carve the words ‘‘HATE ME’’ backward in her forearm. The girl also said she was shackled 12 hours a day, and forced to wear leg restraints to classes, meals and other activities.

Another 15-year-old girl who spent time in Columbia told the AP she was twice groped by a male guard. She said she reported the abuse.

‘‘They told me I was lying,’’ she said with tears streaming down her face. ‘‘They told me that I was wrong for reporting it, that I shouldn’t have brought it up.’’

Columbia sits atop a 2,200-acre campus with a manicured lawn that stretches out beneath the shade of oak trees. From a distance, the red-brick buildings and pastoral grounds could pass for those of a boarding school. Indeed, administrators pointed proudly to the fact that 90 percent of the girls got their general education diploma.

‘‘We are giving them skills that they will take well into adulthood,’’ insisted Richard Harris, a deputy administrator with the Mississippi Department of Human Services — a few weeks before the state announced it was closing Columbia ‘‘due to issues ranging from adequate staffing to quality of care, and the desire to most efficiently spend taxpayer dollars.’’

While officials in many states complain that funding can be a major challenge — salaries for guards in Mississippi’s juvenile facilities start at $18,000 a year — it will take more than cash to fix the problems.

‘‘What could be done to minimize or reduce these problems?’’ asked Melissa Sickmund, with the Pittsburgh-based National Center for Juvenile Justice. ‘‘Training. Oversight.’’

Columbia had about 120 staff members and a $5.8 million budget and at times housed only a few dozen girls. At that rate, it costs about $598 a day to house a girl, according to a study by Timothy J. Roche, an expert consultant hired by the state.

There are success stories.

Nancy Molever, an Arizona Juvenile Department of Corrections spokeswoman, said it would have been difficult to improve conditions there — or meet recommendations made by the federal government — without a willingness ‘‘to change the culture of the agency’’ that oversees the juvenile facilities.

Arizona recently emerged from a lawsuit the Justice Department filed after three youngsters committed suicide. Arizona invested $8 million to $10 million in facility improvements and increased the starting annual salary of youth correctional officers to over $30,000, Molever said. The state has also been weeding out employees slow to conform to the new rules, Molever said, but the downside is more employee turnover, which is already a problem nationwide.

Officials in Missouri, which has one of the most highly regarded juvenile correction systems in the country, agree that it takes more than money to run a safe facility.

‘‘It’s just a different approach that we take. It’s a treatment approach,’’ said Ana Margarita Compain-Romero, a spokeswoman for the Missouri Department of Social Services. ‘‘In other states, they take a more punitive approach, more like corrections.’’