Fernanda Cardona said she was leaving to pick up her son Friday afternoon when he arrived at home by himself.
Cardona said she and her mother normally have to present a blue placard to Park Place Elementary staff in order for her son to be dismissed.
But Friday, the boy told Eyewitness News he was allowed to leave campus by himself.
He said he crossed a street and boarded a METRO bus back to the family's apartment complex about half a mile away.
"He knew how to get home. I'm very thankful for that, but it's just something that's very concerning," Cardona said.
Cardona said she sought answers from her son's assistant principal but wasn't given any.
"She apologized. She explained to me that she doesn't know how this happened. She explained to me that she will be looking at the videos, but she just explained to me that she couldn't do it today because she was busy with the fall festival," Cardona said.
But Cardona said no celebration is that important when a child's safety is in doubt.
"Today was my kid. I don't want it to be tomorrow. Another kid and then a kid goes missing or something happens. A kid is end up dead," Cardona said.
Eyewitness News reached out to HISD but hasn't gotten a response. METRO said it was looking into the matter.
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