Why Them? Separating Vulnerabilities in Rwanda's 2023 Deadly Flood event.

 

Heavy rains in May 2023 battered Rwanda. Rivers overflowed. Hillsides collapsed into mud. When the waters finally subsided, more than 130 lives had been lost on a devastating scale.

News coverage flooded in fast. It tallied casualties. It captured rescue efforts. It shared survivor stories. Yet one key question lingered unanswered: Why those particular victims?

Why did an elderly grandmother perish in her sleep, while her middle-aged daughter nearby made it through? Why did a family in a low-lying home vanish, while uphill neighbors escaped unharmed? Why did so many tragedies strike in the dead of night, not broad daylight?

These aren't grim curiosities. They're vital scientific inquiries. Without addressing them, our flood alerts will repeat, and so will the heartbreak.

Houses that kill and houses that save

In Rwanda, housing quality varies enormously. A reinforced concrete house on a hillside might survive a moderate flood. A mud-brick house in a low-lying area will not. But official vulnerability maps rarely include housing construction type, what make one mud-brick house collapse and other one stand?

I would ask: of the 130 deceased, how many lived in mud-brick vs. fired-brick vs. concrete homes? How many were in valley vs. slopes? How many had a second floor to escape to? Without this data, we build flood models that predict water depth but not who dies.

Why Some Neighbors Survive

Perhaps the most painful question is also the most useful: why was one swept away by raging floodwaters while their neighbor's building collapsed on them? Possible answers include:

One dug a hole in the house to let water flow through; the other lacked a hoe or tools.

One had a family member who woke them; the other lived alone.

One perished from landslide debris, the other from flood surge.

Did all victims die on the spot, or some later at the hospital?

These aren't random factors. They are measurable. And they point directly to interventions: household drainage tools, night wake-up plans, slope stabilization, and better medical evacuations.

The deadly difference of night vs. day

The timing of a flood can mean life or death. Daytime floods give warning signs: dark skies, rising water, neighbors shouting. Nighttime floods give none. People sleep. Rain masks the sound of approaching water.

Many May 2023 deaths occurred between midnight and 7 a.m. That is not a coincidence. It is a design flaw in our early warning systems, which still rely heavily on visual and audible alerts that do not work when people are unconscious.

Age as a hidden factor?

Most disaster reports list ages of the deceased. Few analyze them. In the May 2023 floods, I suspect two age groups were overrepresented: the very young (under 15) and the elderly (over 65). Does the young cannot run or climb to safety?. The elderly may have limited mobility, hearing loss (unable to hear warning shouts), or chronic illness that slows escape.

Working-age adults, by contrast, are more likely to react quickly. If we do not track this pattern, our flood response remains blind. We warn everyone equally, but not everyone can respond equally.

Closing the gap

Most disaster research focuses on survivors. That makes sense survivors can talk. But it creates a blind spot. The deceased cannot speak, but their patterns can. A true vulnerability analysis does not just ask "how many died?" It asks "who, where, when, and in what kind of house?"

Rwanda has made progress in flood mitigation and response. But alone do not save lives. Understanding vulnerability does. The May 2023 floods gave us 130 reasons to start asking better questions. Let us not waste them.