The family of a human rights lawyer crushed to death in the street by half ton windows have called for safety improvements, as a supervisor was found guilty of her manslaughter.
Amanda Telfer, 43, was killed when the stack of large unglazed frames toppled over as she walked past a building site in Mayfair's up-market Hanover Square.
Members of the public rushed to help and lift them off her, but Ms Telfer could not be saved and she was pronounced dead at the scene just before noon on August 30 2012.
Four people and three companies denied all responsibility for the accident, and denied 13 charges relating to the tragic death.
A jury found Kelvin Adsett, supervisor at IS Europe Limited, guilty of manslaughter and breaching health and safety.
IS Europe Limited, of Slough, was found guilty at the Old Bailey of two health and safety breaches.
Damian Lakin-Hall, an employee of Westgreen Construction Limited, was also convicted of failing to take reasonable care of safety whilst at work.
Afterwards, Ms Telfer's parents Barry and Ann Telfer, who had sat through the six-week long Old Bailey trial, said: "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.
"The Health and Safety training being given is totally inadequate, if risk of death to passers-by is ignored.
"It is nearly five years since Amanda died. We would like to thank the police, Health and Safety officers and prosecution who worked on behalf of Amanda for their persistence and patience. We and all Amanda's family and friends will always miss her. Nothing will change that."
The court had heard how the frames, which together weighed 1,444lb (655kg), had been left leaning up against a wall after being delivered the previous day, before the site was ready for their installation.
Prosecutor Duncan Atkinson QC said it was "obvious to anyone" that they carried a "clear and serious risk of death" to anyone walking past.
The frames were seen to move in the wind, prompting concern from the public they might fall into the busy central London street.
Another member of the public had almost been hit in a "near-miss" at the site just days before the fatal accident, the court heard.
Mr Atkinson said: "There were a series of obvious and, in many cases, straightforward steps that could have been taken to avoid that risk, ranging from cancellation, delay, refusal of delivery on the one hand, to the storage, the use of straps and barriers.
"None were taken by any of the defendants and Amanda Telfer died as a result."
Work was "routinely carried out" on the pavement and equipment was stored there overnight, but there was no external barrier to separate the working area from the public, Mr Atkinson said.
Plywood hoarding, painted with Westgreen Construction Limited's logo, had instead been placed inside the building behind the door and window spaces, he said.
He told the jury: "The incident with which this case is concerned was not the first time that the public was put at risk, as it would appear this was not the first incident of its type involving Westgreen's construction site.
"In the days before the accident, a plywood hoarding had fallen from one of the apertures on the building, almost hitting a member of the public as he made his way home."
He told the jury they must consider whether the defendants were aware of what had happened and if this should have caused them to reassess "the sufficiency of the measures being taken to segregate the public from the construction site".
Ms Telfer was working as a freelance intellectual property and media lawyer for publishing houses including Random House at the time of her death.
Lakin-Hall, 48, of Portsmouth Road, Cobham, Surrey, and 65-year-old Adsett - also known as Kelvin Schultz - from New Road, Slough, Berkshire, denied manslaughter and health and safety breaches along with Claire Gordon, 36, of Ashby Crescent, Leeds, who was cleared.
Steven Rogers, 62, of Sheering Mill Lane in Sawbridgeworth, Hertfordshire, was found not guilty of a single charge of failure to take reasonable care for safety while at work as an employee of Westgreen Construction Limited.
Westgreen Construction, of Richmond in Surrey, and Drawn Metal Ltd, of Leeds, were also cleared of health and safety charges.
Judge Peter Rook QC adjourned sentencing until May 5.
Additional reporting by the Press Association.