Building Collapse in Nigeria: An Engineering-Based Analysis of Patterns, Triggers, and Casualties between 2015-2025

Abstract

The collapse of buildings is a major urban safety problem in Nigeria that is driven by the interaction of engineering deficiencies, construction practices, and ineffective regulatory systems. This study presents a spatially informed and engineering-based assessment of building collapse incidents in Nigeria between 2015 and 2025 using secondary data sources. A total of 111 validated collapse events were computed from peer-reviewed literature, media reports, and verified online sources through an adapted PRISMA-based screening process. The descriptive statistics approach was used to analyze trends and spatial distribution by state, building height, condition before collapse, and cause of collapse. Engineering judgment, guided by established structural failure theory, was applied to interpret the dominant failure mechanisms. Findings showed that collapse instances were concentrated in the fast-urbanising states, with Lagos State in particular contributing to over fifty percent of the reported cases. Cases involving low- to mid-rise buildings and structures under construction were the most reported. Structural defects, poor construction techniques, and inferior materials emerged as the top identifiable triggers, while a high proportion of incidents lacked clearly defined causes. Causality analysis revealed 321 deaths and 344 injuries, with an 86% probability of casualty per collapse event. The findings demonstrate that building collapse in Nigeria is a predictable socio-technical problem which requires integrated engineering, regulatory, and institutional interventions to reduce future risks.