Darren Hoofe died in hospital a day after he fell onto the factory floor
A roofer suffered fatal injuries when he fell 20ft (6m) after his boss failed to carry out risk assessment procedures, a court heard.
Darren Hoofe, 20, was carrying out repairs at the Bellbrook Industrial Estate, Uckfield, East Sussex.
He was not wearing a harness and there was no safety net when he fell on 29 November 2005, Hove Crown Court heard.
Colin Cooper, 48, owner of Hailsham-based IC Roofing Ltd, denies manslaughter due to gross negligence.
Mr Hoofe suffered head injuries when he fell through a skylight onto a concrete factory floor, and died in hospital a day later.
Jurors were told that, at an earlier hearing, Mr Cooper, of London Road, Hailsham, pleaded guilty to failing to ensure the safety of an employee under the Health and Safety at Work Act 1974.
The company, an industrial roofing and sheet metal contractor founded by Mr Cooper in 1992, was a "one-man operation", said Brian Altman QC.
He had remained its sole shareholder and director, and had eight employees at the time of the accident.
Mr Altman said Mr Cooper failed to ensure that Mr Hoofe and the two other men working on the site had the necessary safety equipment with them and provided only two harnesses.
"Colin Cooper hadn't correctly assessed the risks to operatives," Mr Altman said.
"He hadn't correctly assessed the risk to them of injury, let alone the risk to them of death - in particular the risk of falls from height - and he had not devised a safe system of work for what was obviously an inherently high-risk situation."
Mr Hoofe, a trained electrical engineer who lived with his parents in Newhaven, was "inexperienced" and had received "limited training" during the six months he had been employed by IC Roofing Ltd, the court heard.
Mr Altman said Mr Hoofe was wearing his own trainers instead of the proper safety boots when he fell.
"The death of Darren Hoofe was entirely preventable had Colin Cooper identified the specific risks involved in the job." he added.
The trial continues.