One worker was killed and three others were injured by a partial collapse, which was to be demolished, on the outskirts of the city of La Louvier in the local authorities.
The accident occurred on a bridge of the E42 motorway crossing a channel at the height of La Louvier.
Mayor Jacques Gobert told the Reuters News Agency that a worker who was in critical condition succumbed to his injuries. His other three colleagues were injured when part of the steel bridge collapsed on a barge that was anchored on the spot to remove rubble.
According to Belga Belgian agency, twelve people were working on the bridge at the time of collapse.