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Published : 28 Aug 2025, 12:00 AM
A bridge over the Shitol Jhorna canal in Chattogram has collapsed during heavy rainfall and hilly runoff earlier this month, with investigators pointing to four key causes.
The 50-year-old brick-laid structure had not been extended or rebuilt despite the canal’s width and depth being increased under a mega project by the Chattogram Development Authority (CDA) to address waterlogging, according to a probe report.
The collapse occurred at dawn on Aug 7, during a spell of intense rainfall.
A portion of the bridge, located in the Star Ship area on Bayezid Bostami Road, gave way, according to the report submitted by a four-member committee formed by Chattogram City Corporation.
Md Anisur Rahman, the city corporation’s chief engineer, led the investigation panel, which handed in its findings on Wednesday.
The report says the bridge in Ward No. 2 (Jalalabad) was built more than five decades ago, using brick foundations with a span of 6m between its sidewalls.
Under CDA’s waterlogging mitigation project, the canal beneath the bridge had been widened to 13m, and its depth had also been increased, along with construction of retaining walls.
“The bridge’s length was not adjusted to the canal’s new width and depth. As a result, during heavy rain and hilly runoff, soil beneath the brick walls on either side was washed away, causing one side of the structure to collapse,” the report reads.
The portion of the bridge on the Oxygen-bound side from Gate No. 2 broke away during the collapse.
Since then, vehicles have only been able to pass over the surviving segment, which the CDA had rebuilt in 2010.
The second cause mentioned in the report involves a drainage channel that was constructed on the eastern side of the bridge. The channel discharged water directly along the base of the bridge’s foundation, weakening its structural integrity over time.
The third factor identified relates to traffic load. When the bridge was built, traffic was minimal in the area. Today, the road sees significantly higher volumes of vehicles, including heavy trucks, lorries, and covered vans, as the area has become an industrial zone. The bridge, designed for lighter use, suffered from excessive stress.
The fourth reason points to two large WASA water supply pipes installed beside the bridge. Connection work and construction of a Reinforced Cement Concrete (RCC) box for pipe protection may also have contributed to the bridge’s damage.
To prevent similar incidents, the probe panel made four recommendations.
The first and primary recommendation calls for demolishing and rebuilding old bridges on city canals, especially where canal width and depth have been increased under waterlogging projects.
The report notes that many canals now have new retaining walls built by multiple agencies. As CDA’s canal dredging deepened the water bodies, earlier retaining structures have started to sink. The panel says these outdated, vulnerable walls should be replaced.
The report also calls for an updated list of bridges and culverts that are not suitable for carrying heavy vehicles. Authorities should install safety signage and, if necessary, ban heavy vehicle movement over those structures.
Lastly, the panel urged caution during utility work involving pipeline installation or relocation, to ensure bridges and culverts are not harmed.
