The Ikeja Cantonment housed the central ordnance depot of the Nigerian Army's 1 Mechanised Division — a stock that had grown unmanageable after the ECOMOG operations in Liberia and Sierra Leone returned heavy munitions to Lagos without a programmed destruction schedule. At about 6.00 pm on Sunday 27 January 2002, a fire that began in a market stall adjoining the cantonment's southern perimeter spread to the bomb store. The first detonation occurred at approximately 6.10 pm; the chain reaction continued until past 10.00 pm, with the largest secondary explosions at 7.45 pm and 9.20 pm registering on seismographs as far as Ibadan.
Live ordnance — 81mm and 120mm mortar rounds, anti-tank rockets, and unexploded artillery shells — was thrown up to seven kilometres from the cantonment, landing in Ikeja GRA, Oshodi, Mushin, Maryland, Oregun and Anthony Village. Residents, believing Lagos was under coup attack (memories of 1976 and 1990 were live), fled south on foot in the darkness. The largest single concentration of deaths occurred at the Oke-Afa Canal in Isolo, where an estimated 600 to 800 people — predominantly women and children — drowned after the leading edge of a fleeing crowd was pushed into the unfenced canal in pitch darkness. Other mass-drowning sites were recorded at the Ejigbo and Egbe drainage channels.
The Federal Government, under President Olusegun Obasanjo, gave an initial official death toll of 1,100. The Lagos State Government, NEMA, the Red Cross and the Civil Defence later put the working figure between 1,100 and 2,000, with more than 5,000 injured and over 12,000 displaced. The Obasanjo administration constituted a Board of Inquiry chaired by Major-General L.P. Ngubane (Defence HQ, March 2002); the report attributed the disaster to (i) the storage of unstable ordnance in proximity to civilian markets, (ii) the absence of a munitions-destruction programme for ECOMOG-returned stock, and (iii) failures in the cantonment fire-response chain. The full report has never been publicly released.
The Oke-Afa mass grave at Isolo holds the remains of more than 600 unidentified victims; a small concrete memorial was erected by the Lagos State Government in 2003 and refurbished in 2017. Compensation paid to identified families was, by the 2012 Senate Public Hearing on Military Welfare, partial and incomplete. The cantonment armoury was decommissioned and the surviving ordnance moved to the Kachia Ordnance Depot, Kaduna, in 2004 — though the underlying problem of storing live munitions inside urban barracks recurred at the Lafenwa, Abeokuta blast (2003), the Lokoja Army Depot fire (2009) and the Borno arms-depot fires (2014–15).
Ikeja 2002 is the worst peacetime disaster in Nigerian military history by deaths. It is recorded here because the institutional cause — urban barracks with uncontrolled ordnance — was a policy decision, not an accident, and remained Federal Government policy long after the disaster.