When it became clear on Monday afternoon that Madison Park Vocational High School students would spend their fourth day of the school year without schedules, 16-year-old Lower Mills resident Kellsi Pemberton decided to do something.

“We just want to go to school, go to our classes, and learn. That’s all we want and the school isn’t giving that to us, so we decided to organize,” Pemberton said.

On Monday, the junior studying culinary arts and her classmates crafted a letter demanding a “functioning and meaningful schedule immediately,” circulating a photo of the letter on social media networks Facebook and Instagram, with a caption calling on students to gather outside of the school on Tuesday morning. They also met with teachers and a representative from the teachers union at an assembly after school on Monday to express their concerns.

But it wasn’t enough.

“Our educational opportunities shouldn’t be less than any high school in Boston,” the letter read. “We find this situation to be outrageous and demand a public apology and meaningful support.” By Tuesday morning, more than 350 students signed the letter.

Instead of walking in to school on Tuesday morning, Pemberton and more than 400 students gathered outside Madison Park Vocational High School, demanding accountability from the school.

The administration heard Pemberton’s message loud and clear: Boston Public Schools interim Superintendent John McDonough arrived at Madison Park at 6:30 a.m., sitting down with teachers, administrators, students, and parents, and pledging not to leave until scheduling was resolved. He told members of the media that he expected all schedules to be set by the end of the day.

“From my perspective, Madison Park must succeed and if we don’t have the schedule right, students are at risk for the entire year,” McDonough said. “That’s not going to happen for me. I did anticipate this would be done before the opening of school. We did run into additional problems in terms of making the schedule work going forward, but we’re in a position now where we have made great progress.”

McDonough stood behind the decision to delay rolling out schedules.

According to BPS policy, all schools set their own schedules, with each headmaster provided access to the computer system used to create schedules. The superintendent’s office also has a central team on the ground to provide support, according to BPS spokesman Lee McGuire.

“If we have students whose needs are not being supported based on where they are assigned, that’s not acceptable,” McDonough said. “And if that means that there may be a temporary delay in issuing the schedule, that’s what it means.”

Tom Parks, a recently retired US History teacher at Madison Park, came to see the protest after former students tipped him off about it the night before. A news helicopter hovered overhead as Parks expressed pride in his former students.

“I came up here to support the students and see their engagement.”

Parks said he is not surprised scheduling proved to be such a headache. With a complex puzzle of vocational students, special education, and ESL, “this is the most complicated scheduling in the city,” Parks said. “The administration knew that. They saw this coming.”

The issues at Madison Park have been long-simmering for the students and family members, as well as a handful of elected officials.

City Councillor Tito Jackson, who was on hand to speak to students following the protest, made an impassioned plea for Madison Park at the city council meeting on Aug. 20. At that time, the school still had 33 unfilled teaching positions. McDonough said all teaching positions but two have been filled, and all administrative positions have since been filled.

“You guys did the right thing,” said Jackson, speaking to a group of six students, including Pemberton. “You stood up and helped make something happen here.”

Two years ago, Parks brought members of the student government to City Hall to get a look at local government in action. Pemberton, then a freshman, was one of those student leaders whom Parks recalled as a standout, highly engaged leader.

“Now she’s making good use of the lesson I was hoping to teach,” Parks said.

Pemberton’s mother Jeanne came to the school after the morning’s protest triggered negotiations with the superintendent and administration officials. Despite the superintendent’s promise to deliver schedules by the end of the day, Jeanne said she will believe it when she sees it.

“This is the only school in Boston Public Schools that can focus on [Kellsi's] dream of becoming a pastry chef when she graduates,” Jeanne said. “If you’re going to take that from my child, I’m going to take my child from you.”

Kellsi and her fellow students pledged to stage another protest on Wednesday if the situation does not improve. Jeanne Pemberton said she also called in a complaint to the Mayor’s office.

“We’re all stressed out," Kellsi Pemberton said. "This is our future we’re talking about. We need teachers that can properly help us and to actually be able to learn."