Fourteen of the Philadelphia School District's most dangerous schools are among the 44 set to close or be relocated, according to an Inquirer analysis.
That includes four neighborhood high schools - Strawberry Mansion, Germantown, Douglas, and Lamberton - that recorded at least five violent incidents per 100 students in 2011-12.
But what impact closing the schools will have on overall safety in the 146,000-student district is uncertain, and some officials say there's the potential for things to get worse.
Some schools will grow larger as they take in students from shuttered buildings. Some young children will have to travel farther to and from school.
And Philadelphia is known for its neighborhood rivalries, which over the years have erupted in violence in and out of school. Students from those varying groups could be forced to cross the turf of their rivals and attend school with them.
"I think it's definitely going to have an impact on safety. How significant, I can't say at this point," said Kelley B. Hodge, the state-appointed safe-schools advocate, who helps victims of violence in district schools. "It's a very intense social experiment. I think every student in the district is going to be affected in some way, shape, or fashion."
The 2011 Inquirer series "Assault on Learning" showed that school violence was a widespread problem in the district, which over the last year has taken steps to improve conditions.
Of the 14 schools with high violence rates set to close, Strawberry Mansion topped the list, with more than 10 violent incidents per 100 students in each of the last five years. Last school year, it was the second-most-violent school in the district.
Ken Trump, president of National School Safety & Security Services, a Cleveland consulting firm, said principals from the sending schools must share information about students with the receiving schools to offset potential problems.
"Neighborhood rivalries and gang rivalries can easily erupt when you mix kids who attend different schools," he said. "It only takes a couple dozen to have a major riot in the schools if you don't know what you're dealing with."
Jerry Jordan, president of the Philadelphia Federation of Teachers, echoed that concern and noted that in Chicago, violence including student deaths followed school closings.
"I think we all learned a lesson from Chicago," he said.
District officials in an interview Thursday afternoon said they were aware of crime patterns and potential problem areas, and would work to make sure all went smoothly.
"Of course, in this process, you're always concerned with safe corridors, making sure students get to and from school safely," said Chief Inspector Cynthia D. Dorsey, who oversees school safety. "It takes sitting down, working out a strategic plan, involving . . . the students, the parents, the administrators, the School District, and the community.
"Key to this is jumping on it now and meeting with the stakeholders. All of us know that student safety is paramount. We don't want any more violence."
Michael Lodise, head of the 385-officer school police union, agreed that mixing students from different turfs poses a major problem.
But on the positive side, he noted that district officials assured him no school police officers would be cut; they would be reassigned to buildings where they are needed.
"We're going to double up on the high schools and middle schools that are going to be open. It will make them a lot safer," he said.
Superintendent William R. Hite Jr. said he had already heard recommendations from administrators on how to ensure safety at schools receiving large numbers of new students in September.
"Principals were asking for opportunities like the summer bridge program so that we can provide conflict-resolution education before the school year begins," he said. (Summer bridge eases the transition for students moving to new schools.)
Some of the $28 million the district will save through the closings, Hite said, will help offset any possible safety issues; other types of programs that could be used are peer mediation and restorative justice, which both use nonviolent methods to curb violence.
Hiram Rivera, executive director of the Philadelphia Student Union, is concerned that students may not be treated fairly when they are forced into an entirely new school culture. Every school, he noted, has its own way of handling discipline, though the district has tried to standardize the response to serious incidents.
"It just changes everything for them in the middle of their high school years," he said, "as they are trying to move on to higher education and the next phases of their lives."
Some high school students said that although their schools weren't scheduled to close, they feared the disruption and potential violence that could accompany an influx of outsiders.
"Students will think they have to protect their school," said Basil Hasan, a 16-year-old junior at William L. Sayre High School.