There's a loud bang, and then it starts: A battery of an electric car is on fire in the test tunnel. A video of the test impressively shows the energy stored in such batteries: meter-long flames flee in disorder and produce enormous amounts of thick, black smoke. The visibility in the previously brightly lit tunnel section quickly approaches zero. After a few minutes, ashes have spread throughout the room.

"In our experiment we were considering in particular private and public operators of small and large underground or multi-storey car parks," says project leader Lars Derek Mellert,"all these existing underground structures are being used to an increasing extent by electric cars. And the operators ask themselves: “【小题1】?"But until now there has been hardly any meaningful technical literature, let alone practical experience for such a case. So Mellert developed three test scenarios（场景）, the results of which were published in a final report in August 2020.

“【小题2】. Besides, they are possibly fatal regardless of the type of drive or energy storage system." says the final report. The primary objective has to be to get everyone out of the danger zone as quickly as possible. The highly poisonous hydrofluoric（氢氟）acid has often been discussed as a particular danger in burning batteries.【小题3】. The real problem, however, is the extinguishing and cooling water that is produced when fighting such a fire and storing a burnt-out battery in a water basin. The analyses showed that some chemical substances in the extinguishing water goes beyond the limit values for industrial wastewater by a factor of 70; the cooling water is even up to 100-times above limit values.

【小题4】Firefighters know that the battery of an electric car is impossible to extinguish and that it can only be cooled with large amounts of water. But this is already known to the specialists and is being practiced.

“WHAT IS CIVILIZATION?” asked Kenneth Clark 50 years ago in the seminal BBC series on the subject. “I don’t know, and I can’t define it in abstract terms, yet. But I think I can recognize it when I see it, and I’m looking at it now.” And he turned to gesture behind him, at the soaring Gothic towers and flying buttresses of Notre Dame.

It seems inhuman to care more about a building than about people. That the sight of Notre Dame going up in flames has attracted so much more attention than floods in southern Africa which killed over 1,000 arouses understandable feelings of guilt. Yet the widespread, intense grief at the sight of the cathedral’s collapsing steeple is in fact profoundly human—and in a particularly 21st-century way.

It is not just the economy that is global today, it is culture too. People wander the world in search not just of jobs and security but also of beauty and history. Familiarity breeds affection. A building on whose sunny steps you have rested, in front of which you have taken a selfie with your loved one, becomes a warm part of your memories and thus of yourself. That helps explain why China is in mourning—WeChat, young China’s principal means of talking to itself, has been throbbing with the story, and Xi Jinping, the country’s president, sent a message of condolence to Emmanuel Macron, his French counterpart—while India was largely indifferent. Tourism from India to the West is a trickle compared with the flood from China.

This visual age has endowed beauty with new power, and social media have turned great works of art into superstars. Only a few, though, have achieved this status. Just as there is only ever a handful of world-famous actors, so the pantheon of globally recognizable cultural symbols is tiny: the Mona Lisa, Michelangelo’s David, the Taj Mahal, the Great Pyramid—and Notre Dame. Disaster, too, is visual. In the 24 hours after the fire started videos on social media of the burning cathedral were viewed nearly a quarter of a billion times.

Yet the emotions the sight aroused were less about the building itself than about what losing it might mean. Notre Dame is an expression of humanity at its collective best. Nobody could look up into that vaulted ceiling without wondering at the cumulative genius of the thousands of anonymous craftsmen who, over a century and a half, realized a vision so grand in its structural ambition and so delicate in its hand-chiselled detail. Its survival through 850 years of political turbulence—through war, revolution and Nazi occupation—binds the present to the past.

The fire also binds people to each other. The outpouring of emotion it has brought forth is proof that, despite the dark forces of division now abroad, we are all in it together. When nationalism is a rising threat, shared sadness makes borders suddenly irrelevant. When politics is polarized, a love of culture has the power to unite. When extremism divides Muslim from Christian and religious people from atheists, those of all faiths and none are mourning together. An edifice built for the glory of God also represents the unity of the human spirit.

And it will be rebuilt. The morning after the fire, the many Parisians who went to the cathedral to mourn its destruction found comfort instead. Although the spire is gone, the towers are still standing and it seems likely that the whole building can be revived. The effort to rebuild it, like the fire, will bring people together. Within 24 hours, €600m ($677m) had been raised from businesses and rich people, and a rash of crowdfunding campaigns started. A high-resolution laser scan of the building, carried out recently, should help.

It will never be the same, but that is as it should be. As Victor Hugo wrote in “The Hunchback of Notre Dame”, a three-volume love-letter to the cathedral: “Great edifices, like great mountains, are the work of centuries. Art is often transformed as it is being made…Time is the architect, the nation is the builder.”

New York factories in the early 1900s were busy and dangerous places to work. Most factories were housed in brick buildings that were overly hot in the summer and extremely cold in the winter. Workers at the time often worked more than 12 hours each day, receiving few breaks and no overtime pay. The floors were crowded with people and equipment, and the doors were often locked to prevent employees from leaving early. In fact, most factory owners and managers mistreated those who asked for changes or directly fired them. The people in charge believed that they did not owe anything more than a paycheck to their workers.

Everything changed when a fire broke out at the Triangle shirtwaist factory in 1911. During that tragic event, about a quarter of the workers (mostly young immigrant women) lost their lives. The factory workers, located on the ninth floor of the building, could not get the door open. The fire escape led only to flames below. The fire truck ladders were not long enough, nor were the water hoses (水管). Fire nets were inadequate.

After the fire, people marched and protested in order to change conditions in factories. Many large protests took place in New York. Eventually, politicians took up the cause, and legislators (立法者) passed workplace laws regulating child labor and the number of workers allowed on a floor. They also called for sprinkler systems (自动喷水系统) to be placed in all factories. The rights of workers were important and valuable.

Today, working in a factory is still a demanding, difficult, and often dangerous job. The victims of the Triangle shirtwaist factory did not die in vain, however. Because of their experience, the workplace was forever changed for the better.