Unstable Foundations: Soil Saturation Behind Mombasa Building Collapse

On November 11, 2024, a tragic building collapse in Mombasa’s Majengo area claimed the life of one construction worker and left four others injured.

Preliminary findings from the National Construction Authority (NCA) attribute the incident to soil saturation caused by a nearby soakage pit, highlighting the critical importance of geotechnical evaluations in construction.

The collapsed 17-storey residential building was still in its early construction stages, with foundation work underway on one side and excavation on the other. The NCA’s initial report suggests that water from a soakage pit seeped into the soil, weakening its load-bearing capacity. A soakage pit, designed for controlled water drainage, must be properly located and engineered to prevent saturation risks. Recent heavy rains in the coastal region, predicted by meteorological authorities, likely exacerbated the already unstable soil conditions, further compromising the site’s stability.

While the project had obtained all statutory approvals, the collapse underscores the need for comprehensive site evaluations beyond basic compliance checks. Following the collapse, a multi-agency response team, including the Kenya Red Cross and local authorities, conducted search and rescue efforts. Two workers were rescued immediately, but the incident highlights recurring issues in Kenya’s construction sector, where inadequate geotechnical assessments have contributed to a troubling series of building failures.

The Mombasa collapse adds to growing concerns over urban construction practices in Kenya. Proper geotechnical assessments, including drainage and soil stability analysis, are vital for long-term structural safety. This incident serves as a reminder that robust planning and proactive risk management are essential to prevent future tragedies in the construction industry.