It was a "breakdown in security arrangements," apparently.
A four-year-old girl was found wandering around a car park in Tesco, after leaving her school unnoticed.
According to
Mirror Online, the girl was able to leave the school on the first day of term after the school's gate was left unlocked.

The child was then found by another parent, who then alerted the school in North Wales.
Bodnant Community School in Prestatyn has apologised for the incident saying it was a “breakdown in security arrangements,” reports the
Daily Post.
Apparently, new measures will be now taken at the school, including a new camera system and electric gates.

The parent told the publication: “I heard the gates weren’t locked at lunchtime and that a child from reception class walked to Tesco car park before a parent, who had kids in the school, spotted the kid and took them back to the school.
“They didn’t even know the child was missing.
“Thank God that another parent found the child, what could’ve happened just doesn’t bear thinking about,” they added.