Four workers were killed when they fell 80ft from a motorway bridge, an inquest heard today.

Post mortem examinations found the four men died of multiple injuries following the fall from under the M5 Avonmouth bridge in September 1999, the jury of five women and three men were told at the start of the Bristol inquest.

Paul Stewart, 23, from Newcastle, Andrew Rodgers, 40, from Middlesborough, Ronald Hill, 38, from Glasgow and Jeffrey Williams, 42, from Newport were working on a gantry suspended beneath the bridge.

Health and Safety investigator Roger Jones explained to the jury how the gantry system worked at the bridge near Bristol.

He told them that one end of the gantry platform had become detached and the men fell to the ground 25 metres below, suffering fatal injuries.

Mr Rogers told the inquest how strengthening work had started on the bridge in 1995 and that in addition work was under way to install new maintenance gantries.

He showed the jury a video of photographs and computer simulation to demonstrate how the gantry system worked.