Toni Boswell, 27, said her son, Dylan Lowe, gave teachers the slip on his first day at St. Thomas' Primary School in Moorside, England, and walked home alone across a busy main road and two side streets, the Daily Mail reported Tuesday.
Boswell said the boy's father, Phillip Lowe, 28, was shocked when the toddler turned up at the family home asking about his mother's whereabouts. She said a teacher from the school arrived after a few minutes to take Dylan back.
"I can't believe this was allowed to happen to my son," said Boswell, who has since moved Dylan to another preschool. "It is every parent's worst nightmare for a child to go missing but for Dylan to run out of school under the noses of teachers is scandalous. I am disgusted that a little child could go home on his own."
Officials with St. Thomas' said the school has added new security measures aimed at preventing similar incidents.