The architecture firm founded by Norman Foster has been cleared over the death of a man killed by a window that fell 90 metres from a newly constructed London penthouse. This was reported by Qazaqyia.kz citing The Guardian.

Foster + Partners (F+P), the practice behind some of the world's most recognisable buildings such as the Gherkin and revamps of the British Museum and Germany's Reichstag, were not held to be responsible for the death of Mick Ferris, a 53-year-old coach driver, in 2018.

However, St James, the project managers of the building where the incident took place, and the project's engineers, Lindner Prater, were found guilty of safety breaches over the death by a jury at Inner London crown court.

Ferris was killed instantly when the 130kg (287lbs) window fell from the penthouse of the Corniche, a luxury tower block development on Albert Embankment, on to the street below.

The jury was told the designers should have considered the risk of the outward-opening, side-hung windows. The court heard that just over a year earlier a window panel had also fallen from the same development. "Miraculously" no one was hurt but no changes were made to the designs as a result of that incident, the court heard.

The prosecution, which was brought by the Health and Safety Executive, said Ferris's death was foreseeable and the designers had ignored concerns about the proven danger of outward-opening windows.

After more than 11 hours of deliberation the jury cleared F+P and the building's design engineer, Wintech. But it found St James and Lindner Prater had failed in their duty to keep the public safe under the Health and Safety at Work Act 1974.

The prosecutor Gordon Menzies told the jury it "wasn't an accident waiting to happen … it was an accident that had already happened in August 2017. The prosecution say it was an accident waiting to happen again."

Ferris was killed by the falling window which had been blown off its hinges when the building was almost complete, the court heard. A woman coming towards him, who was pushing a wheelchair, narrowly missed being hit, jurors were told. A restrictor put in place to prevent the window being blown off had been removed, they heard.

The designers had failed to consider the "catastrophic" consequences if something went wrong with this restrictor, the prosecution said. They also failed to take into account the fulcrum effect of an 85cm (33in) window being prised off its hinges, the prosecution said.

Jurors were told that after the first window panel fell from the building the designers failed to use the incident as a reason to "go back to the drawing board". The jury was told of 12 "missed opportunities" where the designers should have considered the risk of the outward-opening, side-hung windows.

All four defendants denied the charges and claimed they did all that was reasonably practicable to ensure safety.

Menzies told the court: "The wind was sufficiently strong to blow the window open further than 8 and a half inches and the oversailing glass clashed with the frame and, as a result, the hinges were prised off."

Originally the windows had been designed to open inwards, but the design was changed to avoid them clashing with an internal ceiling coffer containing wires and pipes that they would have cleared, the court was told.

It was only after Ferris's death that the window design was changed back to inward-opening, the court heard. The prosecution said F+P should have known such risks due to its specialist knowledge of glass-covered buildings including the Gherkin.

Lawyers for F+P said the firm's role was limited and it was not involved in technical issues. They said it was there to focus on the visual aspects of the design.

A spokesperson for F+P 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 spokesperson for Wintech 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."

A spokesperson for St James 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."

Lindner Prater has been approached for comment.