On 12 May 2017, hospital staff across England reached for patient records and found locked screens instead.

The risk wasn’t new. Neither were many of the vulnerabilities exposed by the crises that followed.

We have accumulated years of reports, inquiries, and recommendations on how to protect critical infrastructure. Yet the distance between identifying a risk and acting on it remains dangerously wide.

These five events span different sectors, continents, and hazards. Together, they show how the rules of resilience have changed and what preparing for the next crisis now requires.

1. The NHS WannaCry attack: when a cyber incident becomes a healthcare crisis

WannaCry was released as part of a worldwide ransomware outbreak in May 2017. It was not designed solely to attack the NHS, but it still affected at least 81 of England’s 236 NHS trusts and hundreds of other health organisations.

Appointments were cancelled, ambulances were diverted, and staff lost access to systems used to communicate and retrieve patient information. Some NHS organisations were unable to use email, forcing teams to coordinate by telephone, personal devices and WhatsApp.

The attack exposed three connected problems.

First, failure can cascade far beyond the system initially compromised. Second, the communication channels needed to manage an emergency may depend on the same infrastructure that has failed. Third, recovery plans are of limited value when they have not been rehearsed across an entire organisation.

Warnings and security alerts had been issued before the attack, but there was no effective mechanism for confirming whether local organisations had acted on them.

The most alarming part was not that the NHS was deliberately selected. It was that it suffered disruption on this scale as collateral damage in a much wider attack.

If a non-targeted attack can disrupt a national health system at this scale, what would a targeted one look like?

2. The Texas winter storm: when risk assessment never becomes risk action

In February 2021, Winter Storm Uri brought extreme cold to Texas and the wider South Central United States. Power plants failed, natural gas production fell, and the state’s grid operator ordered 20,000 megawatts of rolling blackouts to prevent a wider collapse.

More than 4.5 million people in Texas lost electricity, some for as long as four days.

The crisis revealed a circular dependency. Gas infrastructure needed electricity to continue operating, while electricity generators needed gas to produce power. As parts of one system failed, they weakened the other.

But the vulnerabilities were not unknown. Severe cold had caused major disruption in the region in 2011, followed by recommendations on winterisation and preparedness. A decade later, many of the same weaknesses remained.

This is the difference between assessing risk and acting on risk. A vulnerability documented in a report has not been resolved. A recommendation without ownership, funding, testing, and a deadline is not a resilience measure.

The failure therefore began long before the temperature dropped. It began when known weaknesses were allowed to remain operational weaknesses.

3. The Tōhoku earthquake and tsunami: when prepared systems meet a compound crisis

Japan entered 2011 with extensive disaster planning, early-warning systems, protective infrastructure, and a population accustomed to emergency drills.

Then came a magnitude 9.0 earthquake, a devastating tsunami, and the Fukushima Daiichi nuclear accident.

Japan’s preparedness reduced losses in many locations, but the scale and combination of events exceeded assumptions. The earthquake triggered the tsunami. The tsunami cut off power at Fukushima Daiichi and disabled backup generators. Without electricity, critical cooling systems could not operate. At the same time, widespread damage to roads, utilities, communications and supply chains made the response harder.

This was not simply a sequence of three separate emergencies. It was a compound crisis in which one disruption changed the conditions under which every other system had to operate.

That is what cascading failure across non-adjacent systems looks like. A coastal hazard can become an energy emergency. An energy failure can become a technological crisis. Damage to transport or communications can then delay the people, information and equipment needed to respond.

The lesson is not that preparation failed. It is that preparing each system for its own emergency is no longer enough.

4. Hurricane Maria: when recovery capacity is missing

Hurricane Maria struck Puerto Rico in September 2017 and devastated an electricity grid that was already fragile.

Power restoration took roughly 11 months for all customers whose structures were considered safe to reconnect. The resulting outage was the longest in US history.

The storm caused extraordinary physical damage, but the length of the recovery also reflected what had not been put in place beforehand: resilient infrastructure, clear recovery priorities, coordinated decision-making, accessible funding and the capacity to rebuild at scale.

Years after the hurricane, government reviews were still identifying unclear responsibilities and coordination problems between the local and federal organisations involved in reconstruction.

Recovery cannot begin as an improvised project after the event. It depends on plans, agreements, suppliers, skilled personnel, communications, logistics, and financing that exist before the first asset fails.

A system is not resilient simply because emergency power can be restored temporarily. It must also be capable of sustained recovery under damaged, uncertain, and resource-constrained conditions.

5. The Iberian blackout: when local instability becomes a system-wide event

On 28 April 2025, the electricity systems of continental Spain and Portugal experienced a major blackout.

ENTSO-E’s final investigation found no single cause. Instead, the collapse resulted from interacting factors, including oscillations, gaps in voltage and reactive-power control, differing voltage-regulation practices, and reductions in generation and generator disconnections.

Together, these factors led to rapid voltage increases and cascading generation losses.

Interconnected grids are fundamental to modern energy resilience. They allow regions to share capacity, balance supply and demand, and support one another during disruption. But deep interconnection also means that local behaviour can have system-wide consequences.

The Iberian blackout did not demonstrate that interconnection itself is the problem. It demonstrated that interconnected systems require equally connected operational practices, monitoring, data exchange, regulation and decision-making.

Interdependency cuts both ways. It can absorb disruption when systems are coordinated, but it can also allow instability to travel faster than fragmented organisations can respond.

That is why resilience must be designed at the scale of the system, not only at the level of individual assets or operators.

What infrastructure resilience in 2026 now requires

These five crises involved different triggers: ransomware, extreme weather, an earthquake and tsunami, a hurricane, and instability within a modern power system.

Yet the same patterns appear repeatedly:

Systems failed together, not separately. Disruption moved faster than existing response structures. Communications weakened at the moment they were needed most. Recovery took longer than expected. Most importantly, several critical vulnerabilities were already understood before the crisis began.

The next emergency will not wait for organisations to resolve unclear responsibilities, locate resources or discover which plans depend on infrastructure that is no longer available.

Resilience now requires more than identifying hazards. It requires testing assumptions across sectors, preparing for multiple failures at once, and allowing decision-makers to practice under pressure before the consequences are real.

That is the purpose of the Resilient and Renewable Society Summit, taking place in London on 16–17 September 2026. Through plenary discussions, interactive workshops, and a live simulation, participants will examine why systems fail, how disruption spreads across sectors, and what must change before the next crisis arrives.

The summit is free and open to participants across academia, government, industry, policy, NGOs and the wider resilience community.

Register for the RRS Summit at Imperial College London for Free