Two City Council members are demanding answers of Glen Mills Schools and the state agency that supervises it, questioning the safety of children at the private juvenile facility after an assault on a Philadelphia teen by a school counselor.

In a letter to Teresa Miller, head of the Pennsylvania Department of Human Services, Council members Helen Gym and Kenyatta Johnson requested a listing of all violent acts against children detained at Glen Mills over the last decade.

Gym and Johnson, who serve on Council's committee on children and families, also asked for updates on the state's investigation into the teen's assault, as well as a "plan of action" to ensure the safety of boys currently at the school.

"We are outraged about the reported staff conduct, which has led to the physical and emotional trauma of young people who were directly abused or bore witness to abuse," Gym and Johnson wrote in a separate letter to Randy Ireson, the executive director of Glen Mills.

A 17-year-old boy told the Inquirer and Daily News that he was hit in the head, power-slammed to the floor, and choked for several minutes during which he repeatedly told Glen Mills counselors, "I can't breathe." The July 19 attack was caught on surveillance video. The teen said staff tried to keep him from reporting the incident, something the school's leaders deny.

Glen Mills has fired two staffers and suspended four as a result of the assault.

The city has, for now, stopped sending children to Glen Mills, the residential facility in Delaware County that receives the largest number of Philadelphia youth who have committed crimes and are sent to private placements. Nearly 40 percent of the 383 boys at Glen Mills are from Philadelphia.

The 143 boys from Philadelphia currently at the school will remain while the city's Department of Human Services investigates both the July incident and the school's broader operations, Commissioner Cynthia Figueroa said. Her agency is continuing to work with the state and law enforcement, which are conducting their own child-abuse and criminal investigations, respectively.

"The agencies entrusted with our children need to be doing everything in their power to keep our young people safe," Johnson said in an email to the Inquirer and Daily News. "The point of sending the letters is to make it well-known that we have serious concerns here and will be pushing for a wider investigation."

A spokesperson for Pennsylvania DHS said the agency was continuing to investigate and monitor the situation at Glen Mills while cooperating with Philadelphia officials.

"The Department of Human Services takes every allegation of abuse or mistreatment seriously and the well-being and safety of all children across Pennsylvania is always its priority," said Colin Day, the agency's press secretary.

In an emailed statement, Ireson said he and other school leaders "share City Council's commitment to our students, which is why our first priority has and always will be the safety of our students so they may lead full and productive lives."

Ireson said staff "goes through rigorous training."

"We have begun to outreach to City Council and will continue to engage them to address their concerns," he said. Ireson described the July 19 assault as an "isolated incident."

State records show that Glen Mills has fired at least 13 staffers and reprimanded nine more over at least 14 physical assaults on children in the last five years. In an interview, Gym said she wanted to know about violent incidents even if they didn't directly involve Philadelphia boys.

"As we're looking to determine if Glen Mills can handle our youth, we need to be looking at what happens at the facility overall," said Gym. "We're not going to have another Wordsworth."

She was referring to the death of David Hess, another 17-year-old from Philadelphia, who died in 2016 at Wordsworth Academy, a residential treatment facility for juveniles. Hess was heard saying he could not breathe as he struggled with guards who accused him of stealing a cellphone.

His death later was ruled a homicide by asphyxiation. Officials learned of a string of sexual assaults and other problems at Wordsworth, and shut it down.

"Glen Mills is one we want to see work," Gym said, "but we want to know we can guarantee our kids' safety."