Four workers 'died of asphyxiation'
Four workers who were killed in an accident while erecting a steel structure at an industrial site were "asphyxiated", police have said.
The men died on Friday while constructing foundations for a building at an offshore engineering firm's base in Great Yarmouth, Norfolk.
Investigators think the structure at the Claxton Engineering site may have collapsed.
Post-mortem examinations showed all four men died as a result of "asphyxia due to trauma", police said.
Detectives and health and safety experts are investigating and a report is being prepared for a coroner.
Police said the inquiry would be "lengthy and complex".
The men have been named as Adam Taylor, 28, Peter Johnson, 41, Tom Hazelton, 26 and Dan Hazelton, 30.
Two of them were brothers and all four lived near Bury St Edmunds, Suffolk.
Police said Mr Taylor and Dan Hazelton came from Rickinghall, and Mr Johnson and Tom Hazelton from Stanton.