The boy, 15-year-old Alexander Hodkinson, of Bright Street, Cotton Tree, had to be rescued by fire-fighters who broke into the warehouse at LBS Polythene at Standroyd Mill in Cotton Tree Lane, around 8-45 p.m. on Saturday.

Although he had fallen 20ft. through a Perspex roof panel, he suffered only a broken wrist and minor head injuries. He was taken to the Royal Blackburn Hospital for treatment.

Colne Fire Station watch manager Richard Taylor said: "He has been very lucky. He could have been much more seriously hurt. It seems he was jumping from one part of the roof to another to get to his ball and landed on the Perspex and went straight through."

Fire crews had to force their way into the warehouse through the adjacent former Regal Engineering premises. The section of the mill where the accident occurred is one of the smaller parts of the factory - others are three storeys tall with roofs nearly twice as high.

"This should act as a warning to other children if they lose a football in this way - they should keep off the roofs as they can be very dangerous," said Watch Manager Taylor.