Kindergarten students in 2014 were among the first group of children to attend Democracy Prep Congress Heights after a charter network took over a school known as Imagine Southeast. (Astrid Riecken/For The Washington Post)

A prominent Southeast Washington charter school with more than 600 students announced Friday that the coming school year will be its last.

Leaders of Democracy Prep Congress Heights said in an email to parents that the school, which has students in preschool through eighth grade, was unable “to provide Congress Heights scholars the school they deserve.”

The letter said Democracy Prep will seek a new organization to run the campus for the 2019-2020 academic year. School leaders said they are confident they will find a new operator and that students will not have to be displaced.

Democracy Prep, a New York-based charter network, made big promises when it entered the District in 2014 to take over Imagine Southeast, which was on the cusp of being shut down over poor performance.

The charter network had built a reputation for lifting test scores among poor children from low-income families in New York’s Harlem neighborhood and promised to bring its model of college prep and civic education to Washington. The network operates nearly 20 schools across the country, and the D.C. school is the only one it is closing.

“Four years ago, we promised Ward 8 a school in which scholars would thrive academically and socio-emotionally,” reads the letter from Democracy Prep chief executive Katie Duffy and the chair of the board of directors, Jennifer Wider. “Ultimately, we have not been able to deliver on that promise.”

Most students at Democracy Prep Congress Heights are black and come from low-income families. According to city data, the students score below city averages on standardized test scores.

In math, 12 percent of students at the school met or exceeded expectations on a national standardized test. Citywide, 27 percent of students met or exceeded expectations on the test. In English, 16 percent of Democracy Prep Congress Heights students met or exceeded expectation, compared with 31 percent citywide.

The school’s suspension and expulsion rates in the 2016-2017 academic year were drastically higher than citywide averages.

Despite its poor performance, the school attracted a waiting list of more than 100 students in preschool through eighth grade.

Duffy said in an interview Friday that the charter network remained stumped about why its model did not succeed in the District. She said leaders plan to perform an analysis to see if they can figure out what went awry. This is the first school in its network that Democracy Prep has ceased operating, Duffy said.

“We tried every play that we knew that has worked in Camden, Las Vegas, Baton Rouge and for whatever reason, we were not able to meet the needs of the kids, whether that be socially, emotionally or academically,” Duffy said. “And it wasn’t for a lack of support or trying.”

The D.C. Public Charter School Board reviews schools’ charters every five years to ensure they are meeting standards. Democracy Prep Congress Heights was being reviewed. If the school didn’t meet performance benchmarks, the board could have voted to shut it down or put it on probation, demanding the school improve each year if it wanted to remain open.

“Performance at the school needs to improve, and it’s important that Democracy Prep is now taking the step to find a quality operator for the school,” said Scott Pearson, executive director of the charter school board. “Our families and students deserve the best.”

While charter school advocates often view the closing of a low-performing school as evidence of accountability in the sector, other education analysts view it as a sign of instability. Charters are publicly funded but privately operated schools that have more autonomy than schools in the traditional public system.

Cathy Reilly, executive director of Senior High Alliance of Parents, Principals and Educators, a D.C. advocacy organization, said it would prove detrimental for students at the school to potentially have three charter operators with their own leaders and teaching philosophies in five years. She argued the traditional school system offers more stability, because struggling schools simply can’t close and the traditional system offers more support for campuses.

“I would like to see a way that schools like that could come back into [D.C. Public Schools] so there is stability in the system instead of just changing operators,” Reilly said. “It’s confusing for the kids and families.”

Democracy Prep Congress Heights is the latest high-profile charter school to close. The D.C. Public Charter School Board voted in January to close Excel Academy Public Charter School for poor performance. D.C. Public Schools will operate the all-girls campus as part of the traditional public school system. Washington Mathematics Science Technology Public Charter High School — founded in 1998 soon after charter schools were allowed in the District — was shut down over financial mismanagement.

Duffy described the issues at the D.C. outpost of Democracy Prep as an “adult problem” and said they have nothing to do with the school’s “fantastic” students. She said Democracy Prep has no plans to try to open another school in the District.

“Until we deeply understand what happened in Congress Heights,” Duffy said, “we will not be considering expanding in the District.”