A 12-year-old boy has been airlifted to Leeds General Infirmary after falling 50ft through a Holmfirth factory roof.
The youngster was taken to hospital with chest injuries after the fall from the roof of Premier Hank Dyers at about 2.30pm.
He fell through a corrugated asbestos roof at the back of Bottoms Mill, Premier Hank Dyers Ltd's premises.
Charlotte Heaton, an administrator at Premier Hank Dyers, said: "We believe some boys had been climbing on the roof at the back near the pond and one of them fell through the corrugated roof.
"According to my boss he fell about 15 metres. He must have climbed to get up there.
"The first I knew was when the first aider came in with him and it was like: 'Where did he come from?'
"He was very pale and confused. I called an ambulance and he was taken to the first aid room.
"The ambulance came straightaway and the air ambulance and he went to hospital in the helicopter. He's been very lucky."
A Yorkshire Ambulance Service spokesperson said the boy suffered chest injuries which were not believed to be life threatening.