A retired nurse happened to be volunteering at the school when the boy was stricken, and a staffer administered CPR before emergency personnel arrived.
It was not immediately apparent whether the boy - described by a classmate's parent as "a well-liked kid, a sweet kid" - had any preexisting medical conditions. He and his brother, a seventh grader at the school, lived with family at a West Philadelphia homeless shelter.
Galvanized by the boy's death, the community cried out for more Philadelphia School District funding.
Dozens of students, accompanied by teachers and parents, marched late Thursday afternoon to City Hall and then to Gov. Corbett's Philadelphia office to send that message.
Gretchen Elise Walker of Public Citizens for Children and Youth, which organized the march, said the boy's death must serve as a wake-up call to city and state officials to the "desperation of our school-funding situation."
Even Superintendent William R. Hite Jr. drew a connection between the death - which he called a "tragedy" - and funding.
Hite, in a statement, praised the staff who attended to the boy, but said the death "illustrates the serious needs and challenges that our students, teachers, staff and principals face every day. During times of tragedy, our community should not have to question whether an extra staff member or program would have made a difference."
The superintendent urged the city and state to provide an additional $440 million for the next school year.
National, state, and local teachers union presidents also used the boy's death to urge Corbett to direct more money to schools.
Flanked Thursday morning by 50 other parents and supporters of the school, Wilde, the president of Friends of Jackson, addressed the tragedy.
The school at 12th and Federal is a city gem, she said, with 450 students from diverse backgrounds - 35 percent Latino, 29 percent African American, 16 percent white, 14 percent Asian. It offers strong music and art programs, involved parents, and a stable faculty that "work miracles big and small" daily for kids, she said.
But Wilde and others emphasized that as the 7-year-old became ill and died, City Council was questioning district officials over their request for more money.
"We hope," she said, "that debate is now closed."
She also called on city and state lawmakers to ensure that in September, "every one of those schools has a full-time nurse, a full-time counselor, and teacher staffing levels that ensure the safety of our children and give them the opportunity to learn."
Behind Wilde, a steady stream of district staffers entered the school. Grief counselors and principals of surrounding schools came to support those who needed help.
It was the third death of a Jackson student in two years. A kindergartner died of an asthma attack at home last year, parents said, and a 14-year-old was stabbed in the neighborhood this school year.
Gloria Guard said the boy had lived for about a year with his family at Families Forward, the West Philadelphia homeless shelter she directs.
"We are devastated," Guard said. "We are trying our best to support this family, any way that we can. We are working with other families at the shelter to try to get them through this, one teeny step at a time."
At the time the boy fell ill, his class was on the first floor, but he was on the second floor with an aide.
Telling their daughter that her friend had died was excruciating, said Michelle and Jim Kehoe. She asked her parents whether the boy would have a stone with his name on it, like the one memorializing the kindergartner who died last year, placed in front of a tree planted in his honor.
"Everybody was worried that something like this was going to happen," Jim Kehoe said.
Jennifer Singer, another Jackson parent, agreed. She said she knew of a neighborhood family that opted to send their child to private school because they were not comfortable with the idea of there not being a full-time nurse at a school.
She deals with the issue herself.
But "I just don't send my son if I think he's going to have an asthma attack," Singer said.
Avigail Milder, the parent of a Masterman student, lives in the neighborhood and came to the rally to show support for the Jackson community and the call for funding.
There should be more outrage among the community, she said. If city services were at this bare-bones level, "it would not be allowed."
"This is criminal," Milder said. "What are we, a third-world country?"
The Jackson child's death was the second such incident in Philadelphia schools this school year. In October, Laporshia Massey, a sixth grader at Bryant Elementary, died after suffering an asthma attack at school. There was no nurse in the building.
A 2007 National Association of School Nurses study found that 45 percent of U.S. public schools had a full-time nurse in the building. An additional 30 percent had nurses who split their time between schools, and 25 percent had no nurses at all.
Inquirer staff writer Robert Moran contributed to this article.