The student, 7th grader David Fields, was at home in Logan on Friday, hours after the incident.
"I wanted to go home. I was sleepy, tired hungry," he said.
David tells us he took the door leading to that stairwell to try a new route home on Thursday.
It wasn't a stairwell used by students that David found himself in, but instead an emergency stairwell that locked behind him. He said he was trying a new route home after classes let out on Thursday.
His mother, Angela Johnson, suspects a different reason could have led him there. She says David finally admitted recently that he had been the target of bullies.
She told him "You've been going out that way all this time then, out of nowhere - since the bullying started - you decide to go out that way?"
Whatever the reason, he got trapped.
"He was struck in a firewell. Once the door closes behind you it does not open and there's no handle," Johnson said. "It looks like a dungeon and there's no handle on the other side. Then, it's padlocked on the other end."
Family members say they tried the school over the phone and in person multiple times, saying the cleaning staff wouldn't let them in to look.
They filed a missing persons report with police, called David's friends and searched the neighborhood to no avail.
Finally, his father and uncle returned with Philadelphia police who notified school police. They located David just before 12:30 a.m. Friday.
"No one checked the stairwell. They say they checked but apparently no one checked because, if they checked, they would have found him in there," Angela Johnson said.
Philadephia School District spokesman Fernando Gallard says the stairway fire towers should only be locked after the last person in the building has visually inspected them. He adds that the cleaning staff should have notifed someone.
"The staff should have contacted their supervisor and followed procedure to go through the building to check if child a were there," said Gallard. "We will be looking into why that procedure was not followed."
Part of this investigation is to determine if the fire door was padlocked early, or if it was never unlocked that day to begin with. There is no word if any action will be taken against those who may not have followed protocol.