Two companies have been found guilty of health and safety breaches after a coach driver was killed by a falling window pane.

Mick Ferris, 53, died when glass weighing 130kg fell 300ft (90m) from a penthouse flat at The Corniche tower block on Albert Embankment in central London in October 2018.

St James Group Ltd and specialist contractors Lindner Prater Ltd were convicted at Inner London Crown Court of “failing to discharge a duty” under the Health and Safety at Work Act 1974. The firms will be sentenced on 24 September.

Foster + Partners, the architecture firm behind The Gherkin, and engineering consultants Wintech Ltd were cleared of the same charges.

During the trial, the court heard the “extraordinary” fact that a window panel had already fallen from the same development in August 2017, and the design was not substantially changed as a result.

Prosecuting, Gordon Menzies said: “It’s reasonably practicable for clever people to do a simple thing and design a window that doesn’t fall out once every year.”

St James Group took up the role of “principal designer” in 2015, which meant it had a “duty to co-ordinate matters in relation to health and safety”, the court heard.

Foster + Partners, which is behind some of the world’s most iconic buildings, was responsible for the initial designs of the Corniche.

It argued its role did not extend to the technical aspects of the design once the building was in development.

Jurors were told the final design of the window of the Corniche was not safe, because it opened outwards and was held in place by a single metal “restrictor”, and so could be prised off by the wind.

The prosecution said the developers failed to use the first falling window as a reason to “go back to the drawing board”.

Menzies said construction workers were told “not to open the windows at all”, and small written warnings were put up next to the windows for residents.

“Effectively, the designers were hoping the residents would not forget to close their windows,” he said.

It was not until after Ferris’s death that the design was revisited, the court heard.

After the hearing, Health and Safety Executive senior enforcement lawyer James Towey said: “We acknowledge the jury’s verdict and thank them for their service during what was a lengthy and complex trial.

“It is hoped the two convictions provide some comfort to Mick’s family. Our thoughts remain with them at this time.”

A spokesperson for St James Group said: “The death of Mick Ferris in 2018 was tragic. Our thoughts remain with his family and friends. We acknowledge today’s verdict and will carefully consider its implications.”

A Foster + Partners spokesperson said: “Our thoughts remain with Mr Ferris’s family, as they have since October 2018. We note the court’s decision and are grateful to the jury for the time and care they have taken in considering this matter.”

A Wintech spokesperson said: “While the court has reached its conclusion, the tragedy of what happened remains. It is vital that we continue to reflect and learn, and as an industry remain committed to strengthening standards and practices to help prevent such incidents in the future.”

Lindner Prater has been contacted for comment.

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