"There's no control," Helton said.
Bartram made headlines during Pfeiffer's first year there, 1999, when an assistant principal was shot by a student in the school. Pfeiffer said things were worse now.
In interviews over the last week, more than 20 Bartram staffers and students described a school that's often in chaos.
Superintendent William R. Hite Jr., who made his fourth unannounced visit to Bartram on Thursday, acknowledged the school has problems. On Monday, he will send respected former district principal Ozzie Wright to help calm the school.
Hite also said he, the assistant superintendent responsible for the school, and its principal, Kimberly Collins, would work together on Bartram's discipline plan and to emphasize restorative practices, a program that stresses building relationships to prevent conflict.
Bartram, on South 67th Street in Southwest Philadelphia, has long struggled academically, but for a time, its climate was relatively good, thanks to a principal who stayed for a decade and was backed by a large, strong support staff.
But the principal left last year. And this year, the Philadelphia School District's budget crisis has hit hard - Bartram absorbed 100 students from a school that closed, yet still has fewer staffers. Over the last few years, it has lost assistant principals, a disciplinarian, librarian, counselors, and others.
Hite said the school was down two employees over the last year and the issue was "how to effectively deploy the resources that are there."
Now, some teachers say, they have been told not to bother calling for help before 9:30 a.m. because there are no school staffers to assist them.
The school year started badly, with trouble from the opening bell. A new principal was brought in and transferred out after just a few weeks.
Officials later sent two conflict-resolution specialists to help address the climate problem.
One was Stevenson, a district veteran at age 63, and a big man. His job was to greet students as they came in, make sure they were in uniform, and steer them through the metal detector. During class changes, he urged them to move along quickly.
Stevenson used the gentle approach, teachers said. He'd shake the boys' hands, and call, "Good morning, ladies," to the girls.
On March 21, Stevenson was standing in a basement hallway as students walked to class.
For reasons that aren't clear, words with a 17-year-old escalated fast. The teenager knocked Stevenson's clipboard from his hands.
Stevenson bent over, a witness said, and the student grabbed him by the shirt and pushed him against a wall. Stevenson banged his head, hard. The student let go.
"He fell over like a statue, face-first," said Pfeiffer, who was about 25 yards away. "It sounded like a melon hitting the wall."
As Stevenson lay unconscious on the floor, students buzzed around him, snapping photos with their cellphones and shooting videos that soon went viral.
Word quickly spread.
Stevenson suffered a fractured skull, concussion, and other injuries. He has been released from the hospital and is recovering at home. He has declined to comment.
The student was stopped by school police as he tried to run away. He's been charged as a juvenile with aggravated assault, simple assault, and related offenses, according to city police.
A spokeswoman for the District Attorney's Office said the circumstances of the crime did not merit trying the teenager as an adult.
Jerry Jordan, president of the Philadelphia Federation of Teachers, said the attack was the worst since a Germantown High student broke a teacher's neck in 2007. But it fit a recent pattern.
Two staffers had been attacked at Bartram before Stevenson that week.
Last week, the school was locked down after a cafeteria brawl. Six students were arrested.
"There are fights constantly," said one teacher, who asked not to be identified for fear of retribution. "I call downstairs for help - sometimes they answer and sometimes they don't."
Through December, Bartram had nine assaults on students and one on an administrator, according to the latest district figures. In October, there was an incident of "forced oral sex." Records show several students have been robbed. To date at Bartram this school year, the district has reported 34 serious incidents.
Staffers interviewed by The Inquirer say keys, cars, and laptops have been stolen at the school. Some say the district's numbers understate the trouble.
"They've told us we're not allowed to call 911 or we'll be written up," Pfeiffer, the social studies teacher, said. Three others corroborated his account.
District spokesman Fernando Gallard said that did not accord with district practice: "If you have an emergency, you absolutely call 911," he said.
Regardless of the numbers, Bartram is clearly a turbulent place, so much so that science teacher Herman Daniel keeps his door locked during class.
Daniel said that he had a strong relationship with his students, but that it was difficult to keep those roaming the hall from barging into his class.
News of fights and other trouble spreads fast, through cellphones and social media. Students, he said, feel emboldened.
"My ability to exact any kind of repercussions is limited," he said. "There's not much I can do besides talk to them or call a parent."
Helton, the building engineer, said last week a school police officer was struck and his badge snatched by a student. The principal later implored the thief over the loudspeaker to return it, no questions asked. A monetary reward was even offered, Helton said.
"The students take charge," Pfeiffer said. "I got threatened today because I wouldn't let a kid into my classroom who wasn't supposed to be there."
The trouble at Bartram affects more than just safety, staffers say. The problems impact learning and morale.
Many students come to school late or stroll into class whenever they please.
"We have a line of hundreds coming to school after 9 a.m. - mass truancy and tardiness," Pfeiffer said. "How do you educate students who aren't even coming to school on time? The academics have dropped off substantially."
Thirty students are supposed to be in his first-period class, Pfeiffer said. Eight usually show up.
Hite said that on the day he visited last week, about 70 students were in the late room because they were tardy or out of uniform.
And though for the most part it was business as usual in classrooms, Hite said, "there were some classes that were disturbed by students that were in the hallways talking. That was a distraction."
Smoking is common in the school, students and teachers said. On a recent day, Pfeiffer picked up two blunt wraps, two half-smoked joints.
"You can't smoke in a bar in Philadelphia, but you can smoke weed and cigarettes at John Bartram High School," he said. "We just don't have the people to stop that."
There are a number of vacancies at the school, with a number of teachers out for long stretches.
"Some kids have substitutes all day," said the teacher who asked not to be identified. "It's just a warehouse for these kids."
Even veteran Bartram teachers say they're worried.
"I'm even getting anxious to walk the halls any more," said another teacher who asked to remain anonymous.
Staffers like Stevenson are victims, certainly. But others suffer, too.
"There's a lot of talented, intelligent kids there that are getting the bad end of the stick," one teacher said.
Students interviewed at dismissal on Friday talked about fights and rowdy hallways, about trouble in the cafeteria.
"Kids do whatever they want," said senior Catherine Biziens, 18. "There's no structure."
Bartram is "out of control right now," said sophomore Ramira Andrews. She said she used to be afraid. Then, she said, "I got used to it."
215-854-5146 @newskag www.inquirer.com/
Inquirer staff writer Mike Newall contributed to this article.