Joshua Acosta was sitting in a reading classroom Friday afternoon when he passed out and later died at Melrose Park's Gottlieb Memorial Hospital. Autopsy results are pending.
"I'm not going to see my son anymore. That's all I know," said mother Wendy Acosta.
On Saturday, a memorial took shape on the steps of the school, where a steady stream of mourners paid their respects.
Nothing seemed out of the ordinary as Joshua Acosta, the oldest of five children, got ready for school, his mother said.
"He looked at me straight in my eyes and said, 'Bye, Mom.' And I said, 'Bye, baby.' And that was it," Wendy Acosta said.
District officials issued a statement, expressing sorrow at Joshua's unexpected death.