A class of four to six-years-olds was left unsupervised after a village school made an "extraordinary mistake" when it failed to realise a teacher had not turned up for work, a director of children's services said today.
Parents of children at Eppleby Forcett C of E Primary School, near Richmond, North Yorkshire, have been told the youngsters were left alone on Friday and some even went outside before they told staff their supply teacher had not arrived.
Everyone at the school, which only has around 40 pupils, appeared to have assumed the replacement member of staff was with the children, who are thought to have been left to their own devices for more than an hour.
Today, Cynthia Welbourn, the corporate director of Children and Young People's Service at North Yorkshire County Council, said local authority staff were working with the headteacher to work out what went wrong.
She told BBC Radio 5Live: "No-one is more shaken by this than the people in the school itself.
"It is an extraordinary mistake to make but they are very genuine people.
"You can hear from the tone in the headteacher's voice he is very shaken by this.
"Whatever your systems are, the most important thing is human vigilance and the sheer shock that this has given to everybody will make sure that those levels of vigilance are redoubled."
Ms Welbourn said the error was all the more surprising as it was a small school.
Headteacher Stephen Kirby said staff at the school were "very upset and devastated" and steps were being taken to make sure it never happened again.