ONE of the North-East's biggest engineering firms has admitted breaching health and safety law after the deaths of four steel workers, who fell 80ft from a motorway bridge.

Andrew Rodgers, 40, of Coulby Newham, Middlesbrough, and Paul Stewart, 23, of Newcastle, died when they fell from the Avonmouth Bridge, which carries the M5 over the River Avon, near Bristol.

The two other men who died in the accident on September 8, 1999, were Ronnie Hill, 38, of Glasgow, and Jeff Williams, 42, of Newport, Gwent.

Yesterday, Yarm Road Ltd, formerly known as Kvaerner Cleveland Bridge Ltd, of Darlington, and a second company, Costain Ltd, of Berkshire, pleaded guilty to the breaches in a ten-minute hearing at Bristol Crown Court. Both companies could face unlimited fines.

Last night, Lesley Rodgers, the widow of father-of-two Andrew, said: "We still don't really know what happened, and although this will not help the families it is only right they pleaded guilty."

Stephen Climie, prosecuting for the Health and Safety Executive, had told the court of a tragic incident in which the four men plunged to their deaths while working on a gantry underneath the bridge.

The gantry, which was being used to enable strengthening and runway beam replacement to take place, collapsed suddenly, and the men plunged to the ground, landing in fields by the river.

He said: ''Our case is that this incident was caused by a series of management, supervisory and training failures throughout the period from February 6 to September 9.

"The Health and Safety Executive do not suggest that the fatal accident was an isolated incident."

Yarm Road Ltd admitted breaching the Health and Safety at Work Act 1974 by failing to ensure that persons not in its employment, including Mr Hill, were not exposed to risks.

It also admitted failing to ensure the safety of its employees, including Mr Williams, Mr Stewart and Mr Rodgers.

Costain Ltd admitted failing to ensure that persons not in its employment, including Mr Willams, Mr Rodgers, Mr Stewart and Mr Hill, were not exposed to risks.

The case was adjourned to give both companies time to inform the Health and Safety Executive the basis on which they were entering the pleas, and whether there would be any major points of issue.

It is expected to return to court in the autumn.