A supervisor from Slough has been found guilty of manslaughter by gross negligence after a woman was killed walking past a construction site when three half ton window frames fell on her.

Lawyer Amanda Telfer, 43, was crushed to death on Thursday, August 30, 2012 when the large unsecured frames toppled over.

Kelvin Adsett, 64, of New Road, Slough, was convicted at the Old Bailey on Thursday of manslaughter by gross negligence and health and safety offences.

Damian Lakin-Hall, 50 of Portsmouth Road, Cobham, Surrey was convicted of health and safety offences but acquitted of manslaughter.

A company - IS Europe Ltd of Slough - was also convicted of health and safety offences.

Amanda died on August 30, 2012 when the frames together weighing 655kg fell on her, after being left overnight leaning unsecured against a building in Hanover Square.

The convictions follow an investigation by the Metropolitan Police's Homicide and Major Crime Command with the assistance of the Health and Safety Executive.

Adsett and Lakin-Hall were bailed to appear at the same court for sentencing on May 5.

Detective Chief Inspector Andrew Chalmers said afterwards: "The individuals and company who were convicted in this tragic case had a laissez-faire attitude to health and safety and did not take their obligations seriously.

"Each had a responsibility for the safety of the construction site but failed to deal with a basic task that very obviously then presented a serious hazard."

Barry and Ann Telfer, Amanda's parents, said following the verdict: "Amanda was a bright lovely professional woman living her life to the full and making plans for the future.

"Her future was taken from her when she was crushed to death by half ton window frames which took two seconds to fall on her. The frames had been left standing, almost vertically, at the side of a public pavement, unsecured to anything, unattended and with no safety barriers around them.

"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.