As I waded waist-deep in water — with son on shoulder and wife alongside — to flee an Adyar River on steroids, the immortal line from Tennessee Williams’ play ‘A Streetcar Named Desire’ sprang to mind: “I have always depended on the kindness of strangers.”

Unprecedented rains a day earlier had meant that I couldn’t get back home from office — the best I could do was travel to my brother’s house some 4 km away from mine. From there I tried to get an Uber or Ola, but with no cars around the only option was to wait the night out. At the crack of dawn, I trekked to the main road, in steady rain, hoping to find a way back to my apartment in Kotturpuram, close to the banks of the Adyar.

Soon enough an auto-rickshaw arrived warily to the petrol station I had taken temporary refuge in. As the driver was refuelling, I asked him if he would take me to Kotturpuram’s Ranjith Road. The driver replied it was impossible to do so in his small rickshaw as there was too much water on the roads — even SUVs were giving up that side of town.

I couldn’t really blame him as Kotturpuram gets flooded even in moderate rains, and what happened the day earlier was a deluge. But as he got into the rickshaw, the driver asked me, “ Veedu angaya irrukku [Is your house there]?” I nodded and told him that my wife and three-year-old son were alone there, without any means to communicate. He paused. Thought for a couple of seconds, and said, “ Vaanga [come].”

He drove his flimsy rickshaw through streets with water levels high enough to make me lift both my legs onto the passenger seat — and he manoeuvred his vehicle like a champ. But nothing prepared me for what I saw on Ranjith Road. The river, as if it had enough of our jokes about its puniness, had decided to flex its muscles. It had entered my apartment compound through the road on the side and was steadily rising. The Coast Guard was there and so were the people who lived in the slums a couple of streets behind our flat — they had lost their homes.

Thankfully, a small patch of land in front of our main gate was still relatively water free. If I could get my wife and son down fast enough we could make it out of Kotturpuram safely. And that’s what I did.

But as I waded through the waters to our car parked nearby, I realised that though our apartment was on the second floor, we would have been marooned there if I had been even an hour late. Many of my neighbours had also lost their cars in the flood. And that’s when I thought about the kind-hearted auto driver who did not charge a rupee extra and whose name I forgot to ask. That was also when Tennessee Williams’ line about the kindness of strangers came to mind.

Soon it was clear that my experience was not special. In the days that followed there were numerous stories of how people came out to help complete strangers get by through the worst floods in the city's living memory. The citizens of this supposedly conservative city pulled every ounce of strength they had in their reserves and fought back against the fury of nature and official incompetency. It was a time when kindness was the only currency that worked — ATMs, mobile towers and every modern communication tool had gone kaput. >My Facebook post on a medical shop owner who allowed an old lady he had never met before to take home medicines that she couldn’t pay for because of a faulty credit card machine went viral and was shared more than 10,000 times and liked by 35,000 people. Many of those who commented had their own stories to tell.

And this is not special to Chennai alone. Every disaster — be it floods, earthquakes, or war — is replete with stories of those who survived only due to the kindness shown by someone they had never met, someone who expected nothing in return and those who put themselves in harm’s way.

The kindness of strangers has stumped evolutionary biologists who have never been able to explain this trait among living beings satisfactorily so far. Richard Dawkins in his book The Selfish Gene says altruism could be a way for genes to preserve their type by sacrificing the individual. That is, the genes of an animal will make an individual sacrifice its own good so that some other member of the community with similar genes has a better chance to survive and flourish. The gene is selfish. But this does not satisfactorily explain why strangers who have never met before and may never meet again are kind to each other.

There are those who say that altruism or kindness could be a sort of “I will scratch your back now in the hope you will scratch it for me later.” But that would only be true if the other person is around when your back is itchy.

And it also doesn’t explain why, for instance, someone in Beirut is willing to kill himself and his daughter by fighting a suicide bomber and saving the lives of those he had never met? Why should an auto-driver in far away Mumbai forgo his earnings and ask the passenger to instead donate it to flood victims in Chennai? Why should the auto driver in Chennai come to my aid and not charge extra, especially when he would have been better off financially doing so. I was ready to pay double or even three times the normal fare to reach my home that morning.

Even modern businesses have matured into developing ecosystems that depend on the kindness of strangers. Tor, a system for anonymous browsing, depends on web surfers kind enough to share their bandwidth with strangers for it to work. Same goes for torrents. Even crowd-funding for startups and certain causes, by and large, depends on the kindness of strangers.

Why are we kind to those we may never meet again? We don’t know for sure right now. But as Chennai and the dark episodes of terrorism last month in Paris and other places around the world revealed, the kindness shown by strangers is one of those things that make life beautiful.