Contract Scaffolding Services Limited was prosecuted by the HSE following the incident at a factory in Dalston, Cumbria, on 22 February 2013.

Carlisle Magistrates’ Court heard the company had been subcontracted to fit edge protection around the roof of a building, to allow its removal ahead of the building’s demolition.

The 23-year-old trainee scaffolder, from Carlisle, who does not want to be named, was part of a four-strong team carrying out the work. He was wearing a harness, but this was not clipped onto anything at the time of the incident.

He was working on the roof and as he tried to walk past one of his colleagues, he stepped onto a roof light which gave way, causing him to fall through it.

As he fell, he struck parts of the internal steel structure of the building, causing severe cuts to his face and head, before hitting the concrete floor more than six and a half metres below and shattering his knee cap into 12 pieces.

As a result of his injuries, he is no longer able to carry out manual work.

The court was told that although Contract Scaffolding Services  had prepared a scaffolding plan, method statement and risk assessment prior to starting the work, it did not mention the presence of the fragile roof lights.

The scaffolding plan stated that workers would initially work from a cherry picker or scissor lift and that once a single handrail was installed they would gain access onto the roof.

This would prevent falls from the edge but offered no protection from a fall through the roof lights, which ran at four metre intervals and left less than half a metre of usable space where the scaffolders were working.

The plan made no mention of the need to wear a harness when working on the roof and the court heard that although the injured worker was issued with a harness, at five feet the lanyard was so long that even if it had been clipped onto the scaffolding it would not have stopped him falling through the roof lights due to their position.

Contract Scaffolding Services Limited, of London Road, Carlisle, was fined £15,000 and ordered to pay £920 costs after pleading guilty to safety breaches.

Speaking after the hearing, HSE Inspector Martin Paren said: “A worker at Contract Scaffolding Services Ltd has suffered injuries that could affect him from the rest of his life purely because the company failed to make sure its employees were safe.

“The risk of falling through fragile roof lights is well known in the industry but the risk assessment carried out by the company in this case failed to highlight their presence and to ensure a safe system of work was in place to prevent falls.

“A fall from a height of more than six metres could have been fatal. As it is, this young man has suffered serious injuries which could have easily been avoided because his employer failed in its duty to ensure his safety.”