EVERY TIME Marcella Burney gets a call from Andrew Jackson Elementary School, she panics.

That's because three of her children attend Jackson, on 12th Street near Federal in South Philadelphia, including a son who has asthma and a daughter who carries an epinephrine injector because of severe allergies.

"It can be dangerous for kids out on the street, and now we got to worry about our kids in the school, too?" Burney said. "This is very dangerous. It scares me every time I have to leave my kids here."

Burney's concern was echoed by parents and school advocates across the city yesterday, the day after a 7-year-old boy - a first-grader identified by several acquaintances as Sebastian - died suddenly after a medical emergency at the school while no school nurse was present. The boy, who had been living with his family in a West Philadelphia homeless shelter, was taken from the school to Children's Hospital of Philadelphia, where he was pronounced dead about 4:30 p.m.

A spokesman for the city Health Department declined to release the cause of death yesterday, citing privacy issues. "We saw nothing in the autopsy to suggest this is an infectious disease or condition," James Garrow said.

The school has a nurse on Thursdays and every other Friday, the district said.

District officials said that they couldn't comment on whether Sebastian had a pre-existing medical condition, and that it was unclear whether a nurse could have saved him.

The tragedy saddened dozens of parents and supporters who gathered on the front steps of the school yesterday morning as grief counselors and psychologists from the district entered.

The parents decried the lack of funding that keeps full-time nurses and counselors from being employed in most city schools. They demanded full funding - and that city schools not open in September unless each has a full-time nurse and counselor.

The city's public-school students "are denied the basic resources that other children and communities take for granted," said Melissa Wilde, president of Friends of Jackson and a mother of two pupils there. "We will not stand by any longer while the lives of the children of this city are threatened by a lack of basic resources."

On Wednesday, a CPR-certified staffer and a school volunteer who was a retired nurse had scrambled into action when Sebastian collapsed, Wilde said.

"But who will be there next time?" she asked. "What if this school had a full-time nurse? What if this school had a full-time counselor? Could they save the next child's life? We should not have to ask these questions any longer.

"It is time to stop playing politics with the education and lives of the children of this city."

Superintendent William Hite issued a statement calling Sebastian's death a "tragic loss." He offered condolences to the family, friends and the Jackson community, and applauded the school personnel who attended to the boy.

"This incident, however, illustrates the serious needs and challenges that our students, teachers, staff and principals face every day," Hite said. "During times of tragedy, our community should not have to question whether an extra staff member or program would have made a difference. We should all feel confident that our schools have everything they need.

"Our pleas for sustainable funding are based on obvious needs. We urge our funders to provide the school district with the $440 million needed to adequately serve our schools. We cannot afford one more year of inadequately funded schools."

Sebastian's death is the second such tragedy in the district this school year. Laporshia Massey, 12, died in September after suffering an apparent asthma attack at Bryant Elementary in West Philadelphia, where no nurse was on duty.

At City Hall yesterday afternoon, about 50 parents, students and residents rallied in protest over school funding. Then they marched to Gov. Corbett's office at the Hyatt at the Bellevue, calling for the city and state to close the $216 million funding gap for the district.

"This movement has been galvanized and parents have been incensed, and students themselves have been incensed for years," said rally organizer Gretchen Elise Walker, a project director for Public Citizens for Children and Youth. "I don't know what will galvanize more support, but I do think the tragedy does bring additional attention to the fact that there aren't enough resources for basic safety and basic education for our children, and that's not acceptable."

Sebastian and his family had been living at Families Forward Philadelphia, a homeless shelter formerly known as Travelers Aid, on 49th Street near Market in West Philadelphia.

Residents coming out of the shelter yesterday said they did not know the family well or how long they had been there.

Jhyere Brooker, 8, a Jackson second-grader who said he was friends with Sebastian, said he was sick at home Wednesday when the tragedy unfolded. Informed of the news by his older brother, Jhyere inquired further after arriving at school yesterday.

"We asked a teacher more about what happened and she told us, and my heart was broken," he said. "Sebastian was my friend and I really miss him."

Dianne Tran, an Early Head Start teacher who did her student-teaching at Jackson, said she was shocked and disappointed. She said her daughter, Anastasia, previously attended Jackson and once fell and hurt her arm. A school counselor took her back to a classroom and they had to go to the emergency room the next day. Tran said a nurse was not on duty that day and she never received a phone call about the fall.

Her son, Alejandro Tran, a fifth-grader at Jackson, said the school day was "much quieter than usual" yesterday.

"No one really talked, except for lunch," he said.

- Staff writers Dylan Segelbaum, Cindy Stansbury and Vinny Vella contributed to this report.