Watch the coverage of almost any major disaster and a familiar script unfolds. First come the shock and the images of destruction. Within days, the questions follow. Why were some neighbourhoods wrecked while others escaped? Who is to blame for the slow response? And what will change now?

These questions feel urgent and new each time, but they aren't. On All Saints' Day in 1755, an earthquake, a tsunami and a fire tore through Lisbon, and Europe asked almost exactly the same things. Over the two and a half centuries of catastrophes since then, a pattern emerges. Nature supplies the shock, but politics decides who suffers, who gets blamed, and what changes.

In August 2005, Hurricane Katrina's floodwaters did not spread evenly across New Orleans. When the levees failed, the low-lying areas took the worst of it. These included the largely Black and working-class Lower Ninth Ward. Tens of thousands of residents had no car to leave in, and many had nowhere to go and no money to get there.

This wasn't new. During the Great Mississippi Flood of 1927, officials dynamited a levee below New Orleans to protect the city. The blast deliberately flooded poorer parishes downstream. Upriver in Greenville, Mississippi, Black sharecroppers were kept in levee camps and forced to work, while many white residents left by steamboat. In Chicago's 1995 heat wave, the dead were mostly elderly, poor and living alone.

The reason is simple but uncomfortable. Where people live, how solid their homes are, whether they own a car, whether anyone checks on them: all of this is decided long before the storm arrives. Wealthier groups have historically claimed the higher ground and the sturdier buildings. A disaster doesn't create these differences. It reveals them, suddenly and in public.

Takeaway

A disaster works like a stress test of a society's existing structure. It shows where the cracks were all along.

After Lisbon fell, a Jesuit preacher named Gabriel Malagrida declared the earthquake God's punishment for the city's sins. The king's chief minister, the future Marquis of Pombal, saw things differently and spotted an opportunity. He cast the Jesuits as obstacles to recovery, and within a few years he had them expelled from Portugal. Malagrida was later executed.

Blame tends to flow in predictable directions. Sometimes it targets outsiders. After the Great Chicago Fire of 1871, the press fixed on an Irish immigrant, Catherine O'Leary, and her supposedly clumsy cow. After Tokyo's 1923 earthquake, false rumours that Koreans were poisoning wells led to the killing of thousands of Korean residents. Sometimes officials blame each other instead. After Katrina, city, state and federal leaders spent weeks pointing fingers.

Why does this happen so reliably? A disaster creates a sudden hunger for an explanation, and whoever supplies the most convincing story gains power. Blaming a scapegoat draws attention away from slow responses and poor preparation. Blaming a rival weakens them. The question 'what went wrong?' quickly becomes a fight over 'who should pay?'

Takeaway

When catastrophe strikes, notice who is being blamed and ask who benefits from that story. The answer often reveals more about power than about the disaster itself.

In September 1900, a hurricane killed somewhere between 6,000 and 12,000 people in Galveston, Texas. It remains the deadliest natural disaster in American history. The city's old government proved hopeless in the crisis, so Galveston tried something new: a small commission of experts to run the city. Within two decades, hundreds of American cities had copied the model. Galveston also built a seawall and raised the ground level of the entire city.

Disasters can reshape nations, too. In 1970, a cyclone killed hundreds of thousands of people in East Pakistan, and the central government responded slowly. The anger that followed fed an election landslide for Bengali nationalists. After a brutal war the next year, Bangladesh was born. In Lisbon, Pombal rebuilt the city with wide, orderly streets and some of the world's first earthquake-resistant buildings.

But these windows close fast. Political scientists call disasters 'focusing events', because they grab public attention. That attention fades within months. The cameras leave and old interests regroup. Reformers who arrive with plans already drafted tend to succeed, while those who start planning afterwards often miss the moment. And the changes that do happen don't always help the people who suffered most.

Takeaway

Crises rarely produce new ideas. Instead, they give a sudden chance to ideas that already exist, so what changes after a disaster depends largely on what was ready before it.

From Lisbon to New Orleans, the pattern holds across centuries and continents. Disasters expose inequalities that were already there. They set off fierce battles over blame, and they briefly open doors that usually stay closed.

This suggests a different way to watch the next catastrophe unfold. The earthquake or the storm may be natural, but almost everything that follows is shaped by human choices. Who suffers, who gets blamed and what changes are all, to a surprising degree, predictable.