Nigel Chester, 46, of Arnold, Nottingham, suffered serious head injuries after tumbling head first into the void at Premier Foods in Worksop, Nottinghamshire which makes gravy granules and OXO cubes.
But his death was ruled an accident by a jury at Nottingham Council House on Tuesday, after a two-day inquest.
Nigel Chester, 46, of Arnold, Nottingham, suffered serious head injuries after tumbling head first into the void at Premier Foods in Worksop, Nottinghamshire (pictured) which makes gravy granules and OXO cubes
An inquest heard that Mr Chester had been checking smoke detectors at the factory when he used a master key to unlock a first-floor door.
The door was installed 10 years ago when bosses thought a gantry needed to be built above a piece of machinery.
But managers at the food factory decided the gantry was not necessary and the door ‘to nowhere’ was left locked.
A technician revealed that he recently installed a ‘danger’ sign warning about the drop near the locked door. It read ‘Danger. Keep this door locked. Four metre fall to the floor if opened.’
However, Mr Chester, who worked for ADT Fire and Security, had just checked a smoke detector sensor when he accidentally fell 13 foot (4 metres) on May 1 last year.
Accident: Mr Chester’s death was ruled an accident by a jury at Nottingham Council House.
Andrew McNamara, assistant coroner for Nottingham, said: ‘A large piece of equipment required a gantry to be in position above the machinery.
‘A door was installed for access from the first floor but it was then decided the gantry wasn’t necessary.
‘Shortly before the incident, Mr Chester checked a sensor on the first floor. He then unlocked the door and stepped into the void.’
Melvin Lacey, a technician at the factory, said he had given a master key to Mr Chester so he could access a lift room and store cupboards to check the smoke sensors.
He told the hearing the door had been there for about 10 years but had never been opened to his knowledge.
Mr Lacey added: ‘About a month before, we had new printing equipment, so I printed out a bigger version of the sign that was on the door.
‘It said ‘Danger. Keep this door locked. Four metre fall to the floor if opened’.’
Glyn Howarth, a power plant technologist who has worked at Premier Foods for 23 years, told the inquest he rushed to Mr Chester’s aid after the fall.
He said: ‘I heard a bang but it was an alien sound. I didn’t recognise it, so I went to investigate and observed someone on the floor.
‘I then became aware he had a visitor’s name badge around his neck. I called the manager and told him in no uncertain terms that there had been a very serious accident.’
Two other witnesses told the inquest Mr Chester was found bleeding from his head.
Odette Birks, a senior product development technologist, who has been trained in first aid for 24 years, said: ‘It was horrific.
‘He had serious injuries to his head. When I was told, I ran to security to get the defibrillator because I could tell it was serious.
‘I checked his pulse and it was quite strong, and he was breathing, but he didn’t say anything to us.’
McNamara, added: ‘Nigel Chester died at Bassetlaw District General Hospital on May 1, 2013 as a consequence of head injuries following a fall.
‘It’s fairly obvious what happened, for whatever reason, and we’ll never know the reason, he used the key to open the first floor door and fell to his death.
‘It looks as though he struck a pipe and then fell to the floor and sustained what turned out to be fatal injuries.’
A post mortem report, carried out by Professor Guy Rutty, said Mr Chester suffered a number of fractures to his skull.
It added: ‘There was no evidence of drugs or alcohol in his system at the time of his death.’
Premier Foods group manufactures a wide range of foods for companies such as OXO, Ambrosia and Mr Kipling.
The Oxo brand was sold by Unilever to the Campbell Soup company in 2001. Campbell’s UK operation was sold to Premier Foods in 2006.
Simon Antrobus, who represented Premier Foods, said the door had been left there without a gantry for 10 years in case one was needed in the future.
He told the inquest: ‘It was left there to enable flexibility. If the machine had been replaced or moved, the door may have been needed.
‘That is my understanding as to why the door is still there.’