Failures in design, competency and the following of proper procedures led to four Suffolk workers being crushed to death when a reinforced metal cage collapsed on them, the Old Bailey heard today.

Daniel Hazelton, 30, his brother Thomas, 26, and Peter Johnson, 42, all of Stanton near Bury St Edmunds, along with Adam Taylor, 28, of Rickinghall, near Diss, died at Claxton Engineering Services Limited in North River Road, Great Yarmouth, on January 21, 2011.

The company admitted contravening a requirement imposed under the Health & Safety at Work regulations during an earlier hearing at Norwich Crown Court.

Claxton's contractor for the project the four men were working on, Thetford company Encompass Project Management Limited and its director David Groucott, 44, of Hinderclay Road, Rickinghall, also admitted a Health & Safety charge.

Today, the two-day sentencing of the companies and Groucott began at the Old Bailey.

Pascal Bates, prosecuting on behalf of the Health & Safety Executive, told the court the Hazelton brothers, Mr Johnson and Mr Taylor were working in a large metal telephone box-like structure when the tragedy occurred.

Work to put in a high pressure test bay for offshore components was in its early stages.

However, two weeks before the tragedy problems had already begun at the site with pilings and slippage of soil.

The court heard among the shortcomings were no proper support for the sides of the bay, no measures to stop soil falling in further or contamination of the area.

Mr Bates said: 'The list goes on.'

The reinforced steel cage began to be built inside the excavation with the four workers going down into it.

On the morning of the tragedy, Groucott visited the site.

Mr Bates said concerns were raised but nothing was done to stop the work.

The cage had largely taken shape the afternoon it collapsed through what was described as 'racking'.

The court heard what in fact had happened that the pieces of metal had not been connected together correctly.

The cage had been almost two metres high before the collapse. However Mr Bates said afterwards it was measured and found to be only 25 centimetres thick in some places. The four men were in it at the time.

Mr Bates told the court two of the men had been in a position to shout for help. One was still alive for at least 12 minutes after the collapse. However, it was not possible to get anyone out for a further 12 minutes. By this time all four had died.

The cause of death was given as traumatic asphyxiation.

Mr Bates said: 'Simply being unable to breathe because of the pressure of metal upon them.'

Previously the Old Bailey heard Claxton Engineering had taken over the site in 2006.

The company had wanted to replace some of the test bays they had inherited from the former occupant because their conditions were poor.

The bays were for components to be put under pressure to see if they would fail when they were used offshore.

Over the years Claxton Engineering were advised they needed the input of structural engineers, but this was not done until 2010. The project also needed to be supervised by a CDM (Construction, Design and Management) coordinator.

However, no qualified CDM coordinator was appointed.

Mr Bates said Claxton Engineering fell short in choosing Encompass as its principle contractor. There had been a recommendation by Claxton's group chief executive which was followed up by a further instruction specifying Encompass for the job.

It was said that Encompass had previously done building work for a senior manager at Claxton's.

Mr Bates said it seemed to the Health & Safety Executive that Claxton's went ahead 'with the boss's pet builder and didn't think whether the builder could do the job.'

He also said Encompass and Mr Groucott did not have the competencies to do the job.

Mr Bates said Encompass and Groucott agree they were not competent to build what emerged from Claxton Engineering's final designs for the work in 2010.

Encompass had come to the HSE's attention on three previous occasions.

In 2006 it was given a prohibition notice to stop building above ground floor level on a four-storey block of flats in Fishergate, Norwich.

In 2007 in Norwich Road, Hethersett one worker was injured and another left dangling after a platform they were in nearly turned upside down.

Mr Bates said it could easily have resulted in a double fatality.

Two weeks before the quadruple tragedy at Claxton's, another worker fractured his collarbone when he slipped while at work at a location on the Broads.

Simon Antrobus, mitigating for David Groucott and his company Encompass Project Management, said the tragedy had had a devastating effect on the father-of-two.

Mr Antrobus told the court: 'Mr Groucott would wish me before I embark on mitigation to express his regret and remorse for what has happened and his role in what happened.

'He lost friends, as well as work mates, and it has had a profound effect on him. He of course wishes he could turn back time, but he can't.'

The court was told all Groucott could do now was admit his carelessness was, in part, responsible for the loss of life.

Mr Antrobus said: 'On site he didn't believe there was any prospect of that reinforcement cage 'racking' as it did. This is a case of negligence on his part.

'This incident has had an enormous effect on him.'

The Old Bailey heard part of a letter from Groucott's wife Deborah, read out by Mr Antrobus. It stated: 'He lost friends in that incident and is faced by the consequences of that on a daily basis.'

Mr Antrobus told the court: 'They live in a small community in contact with many of the relatives of those who died.'

Mr Antrobus added: 'She makes the point this has changed him for life. He will never get over this terrible accident. It's clear from the pre-sentence report Mr Groucott has been punishing himself on a daily basis.'

Previously, Richard Matthews QC, mitigating for Claxton Engineering, said his client's breach of health and safety regulations accounted to a failure to know how the CDM (Construction, Design and Management) system works.

Mr Williams also said two of the firm's then employees, the procurement manager and health and safety manager, had pointed out what were obvious issues with the work taking place and were given reassurances in that regard.

He added: 'It would be unfair, it would be wrong and positively dangerous if encouraging a culture where people can speak up about matters that causes them a concern. If one creates a culture where people are fearful of speaking up because they will have some responsibility, that would be a bad thing.'

The sentencing continues.