The treacherous snow and ice conditions on the road have already caused the deaths of two motorists, and 16 pupils were lucky to escape unharmed after their school bus skidded off the road and down a 50ft embankment.
According to the Daily Mail, the Stagecoach vehicle was stopped by a tree halfway down a ravine near Caerphilly in South Wales, allowing the Abercarn Primary School pupils, aged between eight and 12, to escape mostly unharmed.
A spokesman from Caerphilly council told the BBC: "We can confirm that a bus carrying 16 pupils was involved in an accident this morning.
"Thankfully there were no serious injuries, but three of the children had minor injuries and were treated by a local GP.
"All the pupils involved have been sent home from school and are with their families."
He added: "We cannot speculate on the cause of the accident as this is being investigated by Gwent Police.
"We have issued advice to our school bus operators to review their routes in light of the continuing weather conditions."
South Wales Fire and Rescue Service said the bus was travelling along a snow-covered hill when it went over the verge and onto the embankment.
"Road conditions in the area are reported to have been icy with surfaces untreated. Safety is our number one priority and all passengers were led safely from the vehicle.
"As a matter of course, we will be assisting the police with their investigation into the incident."
The Big Freeze has seen injuries mounting, with two big sledging accidents leaving a man and his daughter with fractured legs in Scotland and a 16-year-old boy fighting for his life in Middlesborough; a 25-year-old woman was also found dead in the snow after a night out with her friends in Kent.
See a video report here.
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