A construction site supervisor will be sentenced later over the death of a lawyer crushed by half ton windows which toppled over in the street.
Amanda Telfer, 43, was killed when the stack of large unglazed frames collapsed on her as she walked past a building site in Mayfair's Hanover Square.
Members of the public rushed to help, 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.
A jury found supervisor at IS Europe Limited, Kelvin Adsett, 65, of Slough, Berkshire, 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.
Westgreen Construction Limited employee Damian Lakin-Hall, 48, of Cobham, Surrey, was also convicted of failing to take reasonable care of safety whilst at work.
The court had heard how the frames, which together weighed 1,444lb (655kg), had been left leaning 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" 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."
Ms Telfer was working as a freelance intellectual property and media lawyer for publishing houses including Random House.
Her parents Barry and Ann Telfer, who sat through the six-week long 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."
Judge Peter Rook QC will sentence the defendants at the Old Bailey later.