Four Suffolk men died when the steel cage in which they were working collapsed and trapped them underground, an inquest has heard.
The tragedy happened at Claxton Engineering in North River Road, Great Yarmouth where a base was being constructed for a high pressure test bed for components for the offshore oil and gas industry.
Brothers Daniel Hazelton, 30, of Church Meadow, Rickinghall, and Thomas Hazelton, 26, of Duke Street, Stanton, and friends Adam Taylor, 28, of Wheatfields, Rickinghall, and Peter Johnson, 42, of Newlands Close, Stanton, died in an accident in 2011.
The men, working for a firm of sub-contractors, were killed when preparing a steel rod cage being built to reinforce concrete in an excavation about the length of a tennis court.
Detective Chief Inspector Andrew Guy said a probe by the major investigation team and the Health and Safety Executive took 13 months before a file went to the Crown Prosecution Service (CPS) in London .
A year later the CPS ruled there would be no police prosecution for gross negligence manslaughter or corporate manslaughter.
“I asked for a review but the result was the same.” Det Ch Insp Guy said he had just wanted a separate opinion.
Claxton procurement manager Mark Aylen, who acted as liaison with contractors, on the £1.5 million project said a ladder had been borrowed from his company to get in and out the excavation.
He told the inquest he had seen Thomas, one of the team from groundwork sub-contractors Hazegood “squeezing” through the steel structure. Mr Aylen said he had been concerned about the “lack of space within the steel structure with the men working inside.”
He said he had raised this point because of concern of how long it would take the men to get out in an emergency elsewhere on the Claxton site that needed everyone in the area to be evacuated.
He said he had asked a representative of project builders Encompass if it was necessary to do the work in this fashion and been told: “It’s the only way.”
Outlining the incident to the jury, Senior Norfolk Coroner Mrs Jacqueline Lake said: “The steel structure collapsed trapping the four men inside.”
A pathologist found that the cause of death of all four men was traumatic asphyxia.
The hearing at Norwich Coroner’s Court continues today.