Bad engineering is being blamed for the collapse of three major bridges in Papua New Guinea in the past few weeks.
The National Disaster and Emergency services Director General, Eric Ani, said the designers should have considered the soil topography, the force of currents during the raining season and other factors.
He said in the case of the Ramu Bridge in Madang, soil erosion, landslides and heavy debris contributed to its collapse.
Heavy rain had caused strong currents which caused large amounts of debris, including two power pylons, to pile up against the bridge.
The two other bridges damaged after heavy rains were the Whagi in Western Highlands and the Markham in Morobe Province.