Portland limestone quarry company Portland Stone Firms Ltd has been fined £20,000 and ordered to pay costs of £18,992 after a worker fell 4.5m on to a concrete floor, suffering a broken hip and head injuries, while replacing roof lights on a fragile roof.

Weymouth Magistrates’ Court heard on 14 April how a 50-year-old employee from Weymouth, who does not wish to be identified, was on the fragile roof of Portland Stone Firm’s main depot in Easton Street on 16 August 2012.

He was using a ladder and the roof purlins to gain access to the work site because the cherry picker he usually used had been removed from the site by the company.

While replacing a light, he stepped back off the roof purlins and fell 4.5m through the fragile roof and on to the concrete floor inside the building, the court heard.

He suffered a large gash to the back of his head and broke part of his hip bone. He consequently had a number of hip operations and later lost his job with the company.

An investigation into the incident by the Health & Safety Executive (HSE) found that the planning and supervision of the work was inadequate, suitable equipment was not provided and Portland Stone Firms Ltd had failed to ensure a safe system of work.

HSE told the court that safety measures such as working platforms fitted with guardrails, proper crawling boards, edge protection around the perimeter of the roof, safety nets under the roof or a harness system to mitigate any fall should have been put in place by the company.

Portland Stone Firms Ltd pleaded guilty to two breaches of health & safety law, including a breach of the Work at Height Regulations 2005.

Speaking after the hearing, HSE Inspector Mehtaab Hamid said: “Falling from height is one of the most frequent causes of deaths and injuries by workers. The Work at Height Regulations exist to protect people from serious injury and employers who are prepared to put their workers’ lives at risk by breaching them will be prosecuted.

“Employers must ensure that all work at height, particularly work on fragile roofs, is properly planned and organised and that employees are protected from falls.

“Employers have a legal duty to manage safety and failing to do so too often ends in tragedy.”

Further information about working safely at height can be found on the HSE website at www.hse.gov.uk/falls