Mr Akinola, of Littlehampton, West Sussex, suffered life-changing injuries including multiple fractures to his pelvis, leg and arm. He was in hospital for several weeks and was unable to work for nearly a year. He has still not regained full mobility in his left arm.
The incident was investigated by the Health & Safety Executive (HSE), which prosecuted Esher-based Landmark Groundworks Ltd for serious safety breaches.
A nine-day trial at Maidstone Crown Court heard that Mr Akinola was helping to build a large basement alongside an empty house that was being refurbished and extended. Landmark Groundworks was contracted to oversee the project and provide supporting steelwork.
On the day of the incident, a separate subcontractor, Mr Akinola's employer, had laid around 50 concrete floor planks, each weighing up to 2t, for the ground floor. Four planks were laid on a beam that had not been fixed at one end and only held with small welds at the other. As a result the beam tilted and gave way while workers were still on the planks.
Mr Akinola, a plank installer, fell 4m into the basement with the collapsing steel and three of the floor planks. Another worker managed to jump clear as the floor gave way.
HSE's investigation found that Landmark Groundworks, which operates across the southeast, had failed to follow established procedures designed to avoid this type of incident. Landmark had ignored design proposals by two structural engineers that would have helped ensure the project was carried out safely. In addition Landmark did not carry out checks on the installation to ensure it was ready to load out.
The company, of Wren House, Portsmouth Road, Esher, was fined £110,000 and ordered to pay £50,000 in costs after being found guilty of breaching Section 3(1) of the Health and Safety at Work etc Act 1974.
After the hearing HSE inspector John Underwood said: "It is completely unacceptable for a main contactor, Landmark Groundworks Ltd, to allow work to continue with a botched design, and with no checks carried out on either the design or the installation.
"This incident resulted in life-changing injuries to Mr Akinola and it was a matter of luck that the collapse of nearly nine tonnes of building material did not result in multiple fatalities."