Ammunition stores catch fire and explode in populated areas with grim regularity — Misrata on 21 August, N’Djamena in 2024, and dozens of others over the past decade. The recurring question is not why they explode, but why they are inside towns in the first place. There are answers, and they are not mysterious.

What actually happens in a depot explosion

The technical term for what makes these events so destructive is sympathetic detonation. One item of ordnance functions — through fire, impact, or deterioration — and the energy it releases sets off the items stored next to it. Those set off their neighbours. The result is not a single blast but a cascade that can run for hours.

Two things follow from that. The first is duration: emergency crews often cannot approach the site at all while the cascade continues, which is why fires at these sites are typically described as being contained rather than fought. The second is range. A rocket or shell in a burning store is not simply destroyed; it can be propelled, intact or partly intact, well beyond the perimeter, and land somewhere without exploding. Munitions safety specialists call these events unplanned explosions at munitions sites, and international guidance treats the scattering of live ordnance as a defining hazard rather than a side effect.

What the standards say

There is an international reference framework for this. The International Ammunition Technical Guidelines, developed under UN auspices, set out how ammunition should be stored: by hazard type, in separated buildings, with earth barriers between them, with distances calculated from the quantity held, and with an outer separation distance from anything inhabited.

The logic behind separation distance is simply that the cascade has to be interrupted. If one building goes up, the earth walls and the gaps are meant to stop the next one following, and the outer distance is meant to keep the consequences inside the fence. A depot in a city block has none of those things by definition. The guidelines are guidelines: they are not binding law, and states with weak or contested administrations frequently do not apply them.

Four reasons the stores stay put

The city grew around the depot. Many sites were built on what was then the edge of a town, sometimes decades ago, sometimes by a colonial or foreign military. Housing then spread outwards. This is the least political explanation and often the correct one.

The ammunition belongs to a unit, not to a state. Where several armed formations coexist, each keeps what it holds close to its own base and its own people. Moving stock to a remote, monitored location means accepting that someone else could control, count, or destroy it. Security researchers who work on Libya, Yemen and the Sahel make this argument repeatedly. The formations themselves respond that they are providing security the state cannot, and that unilateral disarmament rewards whoever concedes least.

Dispersal is itself a tactic. A single large, well-sited depot is an obvious target from the air. Splitting stock across many small sites — including sites in built-up areas — reduces the loss from any one strike. Ukraine and Russia have both been described as doing versions of this during their war. The humanitarian objection is direct: this shifts risk onto civilians, and where it is done deliberately near protected persons or objects it raises serious questions under the law of armed conflict.

Disposal costs money nobody has budgeted. Surplus and deteriorating ammunition has to be destroyed, and safe destruction is expensive, technical work. Stockpiles that should have been demilitarised years ago instead sit and age, and age is itself a hazard: propellant chemistry becomes less stable over time, which is one of the recognised causes of spontaneous events in old stores.

The danger does not end when the fire does

The phase that follows an explosion is, for civilians, often the more dangerous one. Ordnance thrown clear of the site lands in gardens, on roofs, in fields and on roads. Some of it is armed. Some of it looks like scrap metal. Children are consistently over-represented among the casualties of explosive remnants, because unfamiliar metal objects attract attention.

This is why the routine official line after such incidents — that teams have been dispatched to survey the surrounding area and collect remnants — is not bureaucratic filler. It is the part of the response that determines the casualty count over the following weeks. Where clearance is slow or incomplete, injuries continue long after the story has left the news.

Three questions worth asking about any depot explosion

Has a cause been established, or only asserted? Accident, deterioration and attack all produce similar footage. Early attributions are frequently wrong in both directions.

Is anyone clearing the surrounding area, and is that being reported? If not, expect the injury figure to keep rising quietly.

Does anything change afterwards? Relocation of stores away from housing is the one measure that removes the hazard rather than managing it. It is also the measure most often promised and least often delivered, because the reasons the depot was there in the first place usually survive the explosion.

Related from Plain Sight News: the depot explosion south of Misrata.

Sources: The Libya Observer; background on the 2024 N’Djamena depot explosions; Anadolu Agency.