Building firm fined after house collapse injures four

Aryn Stones Ltd had been contracted to build a new domestic property in Hampstead. On 31 May 2022, remedial works were being carried out on a partially built beam-and-block floor, when it collapsed, taking two of the workers down with it.

The two men include a welder, who is now 62, and a 31-year-old bricklayer. They both sustained life-changing injuries, while two other men who were standing at ground level were injured by falling concrete.

Work on the build began in March 2021 but by February the following year, engineers who inspected the property identified errors with the connections of the structural steel beams. This prompted the remedial works that led the structure to collapse. That came about when the welder was using an oxyacetylene torch to cut a steel beam supporting the first floor. However, at the same time, another worker had been removing some Acrow props that were supporting the beam.

An investigation by the Health and Safety Executive (HSE) found that Aryn Stones Ltd had failed to ensure the structure did not collapse while it was in a state of temporary weakness. The company also failed to put any measures in place to manage the temporary remedial work being carried out on the steel connections. They also failed to take all practicable steps to prevent danger to any person while the building was in a temporary state of weakness.

HSE guidance on managing health and safety in construction (PDF) and the management of temporary works is available.

Aryn Stones Ltd, of Percy Road, London were found guilty of breaching Regulation 19(1) of the Construction (Design and Management) Regulations 2015. The company was fined £50,000 and was ordered to pay £39,000 costs following a two-day trial before City of London Magistrates’ Court on 18 June 2025.

After the hearing, HSE inspector Lucy Ellison-Dunn said: “Although two men were seriously injured, it was lucky nobody was killed.

“This was a completely avoidable incident had a system for the management of temporary works been in place. The company should have taken precautions to protect people from the risk of collapse.

“Everyone working in construction has a responsibility to ensure that everyone on a building site is safe.”

The investigation was also carried out by HSE inspector Alexander McIlwraith.

This prosecution was brought by HSE enforcement lawyer Samantha Crockett and supported by HSE Paralegal Officer Sarah Thomas.