A builder has been jailed for the manslaughter of a woman crushed to death by window frames weighing more than half a ton.

Amanda Telfer, 43, died when a stack of unsecured window frames, weighing 655kg, toppled on to her as she walked past a building site in Hanover Square in Mayfair on August 20, 2012.

Members of the public tried to save her but the injuries sustained by Ms Telfer were too great and she was pronounced dead at the scene just before noon.  

The window frames had been delivered to a construction site and left leaning against a wall.

Your Local Guardian:

Amanda Telfer (Metropolitan Police/PA)

Kelvin Adsett, 64, of New Road in Slough, the supervisor who was responsible for securing the frames, was sentenced to 12 months in prison at the Old Bailey on Friday (May 5), having been convicted of manslaughter by gross negligence and breaching health and safety.

Damian Lakin-Hall, aged 50, and of Portsmoth Road in Cobham, was the site manager employed by Richmond firm Westgreen Construction. He was sentenced to a six-month prison sentence, suspended for two years, after he was found guilty of failing to take reasonable care for health and safety.

IS Europe Ltd, the company which employed Adsett, was found guilty of health and safety charges. The company would have been fined £100,000 but due to their limited assets could only pay £250.

Sentencing Adsett, Judge Peter Rook QC said he had shown “reckless disregard” for what was a life-threatening situation.

He said: “Your actions contributed to the wholly needless and untimely death of Amanda Telfer.”

Following the verdict, Amanda’s parents said their daughter’s future had been taken away because of the construction industry’s “casual approach” to health and safety.

They said: “If construction companies and the people who work for them are not held to account for such high levels of negligence and incompetence then none of us is safe walking the streets next to construction sites.

“The Health and Safety training being given is totally inadequate, if risk of death to passers-by is ignored.”

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Amanda Telfer’s parents Barry and Ann Telfer (Emily Pennink/PA)

The day before Ms Telfer died, the window frames were delivered but were not fitted immediately because of other delays on the site.

They were left on the pavement overnight, unsecured with no barrier around them and no checks were made when the individual defendants arrived the following morning.

As Ms Telfer, a freelance intellectual property and media lawyer, walked past it is believed a door in the building blew open in the wind, hitting the frames and causing them to fall over.

Members of the public managed to lift the frames off her but she was unconscious and not breathing. She died at 11.57am.

Her death was investigated by the Met’s Homicide and Major Crime Command with the assistance of the Health and Safety Executive.

Detective Chief Inspector Andrew Chalmers said Amanda’s death was “completely avoidable”.

He said: “I hope this case will serve as a stark reminder to others that health and safety laws exist for a reason and must be adhered to.”

Graham Partridge, London CPA reviewing lawyer, said: “The CPS case was that the defendants’ conduct was so bad that those involved bore criminal responsibility for Ms Telfer’s tragic death.

“We hope that these convictions will bring some sense of justice for her family.”