Built systems

Partial or total failure of a building from design, construction, maintenance, overload or hazard damage, trapping occupants.

Failure of building-envelope elements, such as cladding, that fall, carry fire up a building face or expose occupants.

Also: cladding fire, falling facade

Collapse or failure of towers, stands, cranes, masts and other structures that are not buildings.

Also: crane collapse, tower collapse, stand collapse

Collapse or loss of function of a bridge from scour, overload, fatigue, impact or hazard damage, cutting a route and often killing people.

Collapse, flooding, fire or ventilation failure in a tunnel that traps people and cuts a route.

Breach or collapse of a dam, sending a sudden flood wave downstream.

Also: dam breach, dam collapse

Failure of an embankment or flood wall, by overtopping, seepage or erosion, that lets protected land flood suddenly.

Also: flood wall failure, embankment failure

Failure of a pipeline carrying gas, oil, water or chemicals, releasing its contents and risking fire, flooding or poisoning.

Also: pipe burst

Loss of electricity supply across a large area, stopping water, heating, cooling, communications and health care.

Also: blackout, grid failure

Loss of piped water of safe quantity or quality, from pump failure, mains break, treatment failure or contamination.

Also: mains failure, treatment failure

Blockage or overload of sewers and drains that spills sewage into streets, homes and waterways.

Also: sewer flooding, drain blockage

Loss of gas supply, or a gas network leak and explosion, that leaves homes and industry without heat and fuel.

Also: gas outage, gas leak explosion

Loss of radio, cellular, fixed or broadcast communications over an area.

Also: phone network outage, radio outage

Loss of the systems people use to call for help or to receive warnings, including emergency numbers, alert broadcasts and responder radio.

Also: emergency number outage, warning system failure

Crash, collision or loss of control of an aircraft, or a major incident at an airport.

Also: plane crash, airport incident

Sinking, collision, grounding, fire or capsizing of a sea-going vessel, with loss of life and pollution.

Also: ship sinking, vessel collision

Capsizing, collision or sinking of boats, ferries and barges on rivers, lakes and canals.

Also: ferry accident, boat capsizing

Derailment, collision or fire on a railway, including crashes at level crossings.

Also: train derailment, train collision

Collision or loss of control of a road vehicle, singly or in multi-vehicle pile-ups, the largest transport cause of death.

Also: traffic accident, pile-up

A sudden blast from combustible dust, gas, vapour or reactive chemicals at a plant, store or mine.

Detonation or violent fire of stored reactive chemicals, such as oxidiser stockpiles, in ports and warehouses near people.

Also: oxidiser stockpile explosion, warehouse blast

Fire at a plant, warehouse or storage site that spreads, emits toxic smoke and may set off further releases.

Also: warehouse fire, plant fire

Fire in a building that spreads to neighbours, or across dense or informal settlements, killing and displacing people.

Also: house fire, urban fire, informal settlement fire

Unplanned detonation or fire in the making, storage, transport or use of explosives.

Collapse, flooding, gas explosion or fire underground or in open pits, trapping or killing miners.

Also: mine collapse, mine flooding, firedamp explosion

Blowout, fire, explosion or structural failure at a well, rig or processing facility.

Also: well blowout, rig fire, platform accident

Self-heating failure of lithium batteries in storage plants, vehicles, devices or waste that causes intense, reigniting fire and toxic gas.

Also: lithium battery fire, energy storage fire, e-bike fire, Grid battery storage fire, battery energy storage fire, thermal runaway, Battery storage fire and thermal runaway, lithium-ion fire

Leak of hydrogen from production, storage, pipelines or refuelling that ignites easily and burns or explodes, an emerging hazard as use grows.

Also: hydrogen leak, hydrogen fire, Hydrogen leak, fire and explosion, hydrogen explosion, hydrogen embrittlement, Hydrogen leak and explosion

Violent rupture of a vessel holding liquefied gas, heated by fire, that throws a fireball and fragments across a wide area.

Also: BLEVE, LPG explosion, LNG fire

Fire or explosion at a fuel or chemical tank farm that spreads between tanks, burns for days and pollutes air, land and water.

Also: oil depot fire, tank fire

Loss of control of a heat-releasing chemical process that over-pressurises equipment and leads to explosion or toxic release.

Also: reactor runaway, thermal runaway in process

Collapse, gas escape, polluted water outbreak or open shafts from closed or abandoned mines, often long after operators have gone.

Also: mine water rebound, old mine collapse

Collapse, landslide or flooding at informal and small-scale mines worked without engineering, killing many diggers at once.

Also: artisanal mine collapse, small-scale mine landslide

Disabling, bypassing or overload of alarms, trips and relief systems at a hazardous plant, leaving no barrier when a process goes wrong.

Also: safety instrumented system bypass, alarm overload

Loss of stable grid operation when little rotating generation remains online, so disturbances change frequency and voltage too fast for protection and control to respond.

Also: low system strength, weak grid instability, Inverter-dominated grid instability, low-inertia grid collapse, inverter trip cascade, Power-grid stability event, frequency collapse, voltage collapse

A sudden imbalance between supply and demand that drives grid frequency outside safe limits, tripping generators in a chain and blacking out a whole synchronous area.

Also: under-frequency collapse, frequency excursion

Progressive fall of voltage across part of a grid when reactive power support runs out under heavy load, ending in widespread tripping of lines and customers.

Also: voltage instability

Simultaneous disconnection of many solar, wind or battery inverters after a grid fault because of shared settings, turning a small disturbance into a large supply loss.

Also: inverter ride-through failure, distributed generation trip

Growing oscillations of power flow between regions or between converter controls that damage equipment and force lines and plants offline.

Also: inter-area oscillation, control interaction

A sustained gap between available generation and demand, from plant retirement, fuel shortage or slow build, that forces planned rotating outages over weeks or years.

Also: capacity shortage, rolling load shedding

A prolonged spell of calm, overcast weather that cuts wind and solar output across a wide area while demand stays high, draining storage and reserves.

Also: dunkelflaute, renewable lull

Loss of hydroelectric output when low inflows and drawn-down reservoirs limit generation, forcing costly substitutes, load shedding or export cuts.

Also: low reservoir generation

Forced reduction of nuclear and fossil plant output when river or sea water is too warm or too low to cool them within environmental and safety limits.

Also: river temperature derating, cooling water shortage

Loss of both grid connection and backup power or cooling at a nuclear site, which threatens core and spent-fuel cooling and can lead to a radiological accident.

Also: station blackout, loss of off-site power

Military action at or near a nuclear facility that cuts power lines, staff and supplies or damages structures, raising the chance of a radiological release.

Also: occupied nuclear plant, shelling near a reactor

Destruction or failure of high-voltage transformers, by fault, fire, attack or induced currents, that takes years to replace and leaves a region weakly supplied.

Also: transformer failure, substation destruction

Sudden loss of a large link between grids or countries that removes imports at once and can unbalance both connected systems.

Also: HVDC link outage, interconnector failure

Inability to restart a blacked-out grid because restart plants, communications or fuel are unavailable, so an outage lasts days rather than hours.

Also: black start failure, failed restoration

Fall of pressure across a national or regional gas transmission system when supply cannot meet demand, forcing firm load cuts and risking unsafe relighting of millions of appliances.

Also: gas system pressure loss, national gas emergency

Running down of underground and liquefied gas stocks before winter ends, leaving no buffer against cold spells or import loss.

Also: low storage stocks

Shutdown of refineries, fuel terminals or delivery fleets that empties filling stations and stops emergency vehicles, generators and freight.

Also: refinery outage, fuel terminal shutdown, filling station run

Structural, mechanical or cable failure of offshore wind farms or platforms, from storm loads, fatigue, corrosion or collision, cutting supply and risking pollution.

Also: offshore wind turbine failure, foundation failure, offshore platform loss

Ignition of vegetation by sparking, falling or clashing power lines in wind and drought, starting fast fires near communities.

Also: utility-caused wildfire, conductor clash ignition

Deliberate switching off of power lines during extreme fire weather that protects against ignition but cuts supply to communities, wells and medical devices.

Also: public safety power shutoff, wildfire de-energisation

Rapid growth in electricity demand from data centres, electrified heat and transport or industry that outpaces grid and generation build, eroding reserve margins.

Also: data-centre load surge, electrification demand shock

Overloading of local cables and transformers by clustered heat pumps, vehicle chargers or rooftop solar, causing outages and blocking new connections.

Also: local grid congestion, feeder overload

Breakdown of a sewage treatment works from power loss, flooding, overload or process upset, releasing poorly treated effluent into rivers and coasts.

Also: treatment works failure, sewage works outage

Entry of sewage, soil water or chemicals into drinking-water pipes through low pressure, backflow or breaks, causing waterborne illness downstream of treatment.

Also: backflow contamination, pressure transient intrusion

Wrong dosing of disinfectant, coagulant or other treatment chemicals, by fault, mistake or tampering, that leaves water unsafe or poisonous.

Also: chemical overdose in water, disinfection failure

An extended order not to drink tap water after contamination or loss of treatment, which burdens households, hospitals and food businesses.

Also: boil-water notice, do-not-drink order

Loss of output from a desalination plant through power loss, intake fouling by algae, oil or jellyfish, or attack, in places that rely on it for most drinking water.

Also: desalination shutdown

Loss of the river, reservoir or aquifer intake that feeds treatment, through pollution, low level, silt, algal toxins or ice, shutting supply at source.

Also: intake contamination, source outage

Persistent loss of treated water from ageing pipes that wastes supply and energy, lowers pressure and lets contaminants in.

Also: non-revenue water, pipe leakage

Piped water delivered only for hours a day or week, which drives unsafe storage, contamination on refill and unequal access.

Also: rationed piped water, water by rota

Insufficient water pressure or volume for firefighting when networks are damaged, drained or overwhelmed during large fires.

Also: hydrant failure, fire-flow loss

Loss of a data centre through power, cooling, fire suppression or flood failure, taking down the hosted services of many organisations at once.

Also: data centre power failure, data centre cooling failure, Data-centre hub failure, data-centre cluster outage, data-centre cooling failure

Fire in a data centre, often from batteries or electrical faults, that destroys equipment and stored data and can cause lasting loss of services.

Also: server hall fire, battery room fire

A software, configuration or hardware fault in the central systems of a telecom operator that cuts calls, data and emergency access nationwide.

Also: carrier-wide outage, core signalling failure

Severing of long-distance fibre routes by digging, fire, flood, landslide or sabotage, isolating regions where routes lack diversity.

Also: fibre cut, backbone severance

Loss of a facility where many networks or subsea cables meet, which concentrates traffic and can cut a country's links to the wider internet.

Also: exchange point outage, cable landing station failure

Loss or corruption of the precise time reference that networks, grids, markets and telecoms depend on, causing errors, rejected transactions and outages.

Also: timing loss, clock fault, Precision timing failure, timing outage, clock synchronisation failure, PNT timing loss

Failure of mobile masts and exchanges when batteries and generators run out during long power cuts, ending communication just when it is most needed.

Also: mast battery depletion, cell site outage

Loss of radio and television transmitters through fire, power loss or attack, removing a key channel for public warnings.

Also: radio and television transmitter outage

A failure of a satellite navigation system itself, such as a bad upload or clock fault, that degrades or falsifies positions and time worldwide.

Also: constellation failure, navigation signal error

Loss of satellite communication or broadband services from satellite, ground station or software failure, cutting links for ships, aircraft, remote areas and responders.

Also: satellite internet outage, satellite link loss

Loss of, or delay in replacing, weather and Earth-observation satellites that degrades forecasts, warnings and environmental monitoring.

Also: weather satellite loss, observing gap

Loss of the stations and control centres that command satellites and pass their data, cutting service even though satellites stay healthy.

Also: ground station outage, satellite control centre failure

Rupture or damage of a seabed gas or oil pipeline by anchors, trawling, corrosion or sabotage, cutting supply for months and releasing gas or oil.

Also: subsea pipeline sabotage, pipeline anchor strike

Failure or cutting of a seabed power cable from a wind farm, island or neighbouring grid, which takes months to repair with scarce vessels.

Also: export cable failure, interconnector cable cut

Deniable attacks on seabed cables, pipelines or sensors by state-linked vessels or drones, designed to disrupt without open war.

Also: grey-zone seabed attack, shadow fleet anchor dragging

Failure of air traffic control systems, staffing or data that forces flight restrictions or grounding over a large airspace.

Also: air traffic control outage, flight plan system failure

Closure of airspace over a country or region because of conflict, ash, missiles or political decision, rerouting or grounding air traffic.

Also: no-fly zone, flight ban

Loss of signalling, traction power or control systems across a rail network that strands trains and halts passenger and freight services.

Also: signalling failure, traction power loss

Sideways buckling of rails under high temperatures that derails trains and forces speed limits across networks.

Also: rail buckle, sun kink

Closure of a main road, pass or crossing by collapse, landslide, snow, flood or protest, with no practical diversion for freight and emergency traffic.

Also: highway closure, mountain pass closure

Fall of river or canal levels that cuts barge loads or halts inland shipping, raising freight costs and stranding bulk supplies.

Also: low river level shipping halt, barge draught limit

Failure of a lock, gate or canal structure that closes an inland or ship canal route until it is repaired.

Also: lock gate failure, canal closure

Crash or derailment of a road tanker, rail car or vessel carrying hazardous goods that leads to fire, explosion or toxic release among nearby people.

Also: tanker crash, hazmat train derailment

Fire in a ship's cargo, often from misdeclared dangerous goods or batteries, that crews cannot reach, leading to loss of the vessel and pollution.

Also: container ship fire, vehicle carrier fire

Loss of containers from ships in heavy seas, releasing goods and chemicals and leaving floating hazards to other vessels.

Also: containers overboard

Illegal tapping of fuel pipelines that causes leaks, fires and explosions among people collecting fuel, and pollutes land and water.

Also: fuel theft tap, bunkering tap

Loss of an urban metro, tram or bus system through power, control or flood failure, stranding commuters and overloading roads.

Also: metro shutdown, transit network outage

Loss of stored grain and staple food to pests, moisture, mould, collapse or destruction of silos and stores, reducing reserves and food safety.

Also: post-harvest loss, silo failure, grain spoilage

Failure of canals, pumps, wells or barrages that supply irrigation water, ruining crops in a growing season across an irrigated district.

Also: canal breach, irrigation pump failure

Shutdown of one of a few large plants that process a staple, such as meat, milk, grain or infant formula, causing shortages and waste upstream.

Also: meat plant closure, processing plant shutdown

Running down of public grain or food reserves below what is needed to buffer price spikes or emergencies.

Also: grain reserve exhaustion

Loss of fuel or electricity for pumping, drying, milking, refrigeration and machinery that stops food production during critical seasons.

Also: farm diesel shortage, pumping power loss

Indoor temperatures in homes, care settings, schools and hospitals rising to harmful levels because buildings trap heat and lack shading or cooling.

Also: indoor heat, overheating homes and wards

Large numbers of buildings built without adequate engineering or to old codes, which collapse in earthquakes, storms or floods and cause most disaster deaths.

Also: non-ductile buildings, soft-storey buildings, unreinforced masonry

A construction material or system found to fail, burn or decay faster than expected after wide use, forcing closures and costly remediation across many buildings.

Also: failing lightweight concrete, combustible insulation

Collapse of buildings under construction, scaffolds, excavations or temporary supports that kills workers and passers-by.

Also: scaffold collapse, excavation collapse, formwork failure

Ground movement from tunnelling, deep basements or dewatering that cracks nearby buildings, pipes and roads.

Also: tunnelling settlement, basement dig damage

Failure of escape routes, lifts, alarms or strategy in a tall building during fire or outage, trapping occupants.

Also: tower evacuation failure, stay-put failure

Gradual loss of strength and function in bridges, pipes, dams, lines and buildings past their design life, raising the chance of sudden failure.

Also: asset decay, structural degradation, Ageing infrastructure deterioration, deferred maintenance, infrastructure decay

Accumulation of postponed inspection, repair and renewal of assets under budget pressure, which hides risk until failures cluster.

Also: maintenance deficit, underinvestment

Corrosion of steel and chemical decay inside concrete, often hidden, that weakens bridges, car parks, piers and buildings until parts fall or collapse.

Also: rebar corrosion, concrete cancer, alkali-silica reaction

Growth of cracks in steel structures, rails, pipes and machinery under repeated loading that can end in sudden fracture.

Also: fatigue failure, weld cracking

Many dams reaching or passing their design life, with silting, outdated spillways and weak foundations, under heavier floods than they were designed for.

Also: old dams, silted reservoir

Reliance on old control systems, software and parts that are no longer made or supported, so faults cannot be fixed and security cannot be patched.

Also: obsolete control systems, unsupported software, spare parts obsolescence

Loss of the engineers, operators and trades who run, inspect and repair critical systems, through retirement and under-training, slowing repair and raising error.

Also: engineering workforce gap, operator retirement