We were living on the Upper East Side, about 5 miles from Ground Zero. As I walked west, there were no cars in sight, save the occasional police car or random bus. Near stretches of the avenues with restaurants, I saw something that didn’t make sense: They were packed. Corrals of tables colonized the empty streets. Diners leaned back, eating, drinking, talking, smiling, laughing. It was as though the most buoyant of New York City nights from the distant carefree past had been bottled and released as a countermeasure into this new, tense world.

That night I realized lots of people, when subjected to the stress of an unexpected crisis, want to party. You could view this social bravado as an act of heroic defiance, an affirmation of community, a foolish denial of danger, or just an overwhelming need to be around others in trying times. You couldn’t view it as new: Italian poet Giovanni Boccaccio, setting the scene for The Decameron in plague-stricken 1348, reports on those Florentines whose remedy was “to carouse and make merry and go about singing and frolicking and satisfy the appetite in everything possible and laugh and scoff at whatsoever befell.”

So a few weeks ago, before states issued social-distancing directives, I wasn’t surprised to see images of people waiting in huge lines to get into bars in South Boston or hanging out on their laptops in my local coffee shop in Rhode Island, on Providence’s West Side. At a popular beer hall around the corner, it was brunch as usual for the 20- and 30-something crowd.

On that particular day, the patrons may have seen that the number of coronavirus disease (COVID-19) cases in the state stood at 20, with another 57 tests pending, and added that to the approximate number of people in quarantine to get a number under 700, in a state of 1 million people. (That was Sunday, March 12, and those figures are now quaint historical curiosities compared to the current situation).

We know, intellectually, that a disease’s communicability does not adjust according to one’s perceived chances of getting it. Nor does it respect the sanctity of social niceties. But until they actually feel in danger, people cannot be trusted to take all the precautions they should all the time, so the main recourse governments have is to clear out and lock up public places. For the sake of public health, follow Public Enemy’s 1991 advice: Shut ’em down.

But this creates an additional problem, the economic one, and the news now focuses almost as much on the coming downturn as on the pandemic itself. We have some experience: After 9/11 in New York, along with lines to give blood, so, too, came forth the rallying cry to spend money at downtown shops and restaurants. But several months later, the Small Business Administration had extended loans to only about 25 percent of the 18,000 small businesses affected by the attacks. It’s estimated that 9/11 led to the loss of 430,000 jobs in the city and pushed the unemployment rate up by more than 2 percent. Tourism plummeted; hotels laid off 3,000 people in the week after the attacks.

An attack or an earthquake or a hurricane is an acute shock, followed by a period of assessment and rebuilding. Financial and social capital are deployed, often spanning years, to foster recovery. For me, the emotional strain of 9/11 in New York was somewhat allayed years later, when I took a job helping to design new infrastructure at the World Trade Center.

A pandemic creates widespread, disaster-level economic damage without much need for physical building. Workers in Wuhan, China, built a large prefab hospital, albeit spartan, in 10 days. Given the multitude of time-lapse and drone footage available showing the construction, the authorities must have considered this as much a morale boost as a public health one. But who knows how or if that instant facility can continue to be economically viable after the crisis abates? If left standing, it will serve in part to remind us of the pervasive fear caused by a pandemic, which comes in waves as various pieces of information tumble into public discourse.

One researcher has concluded that during the SARS (severe acute respiratory syndrome) epidemic, 20 percent of the economic damage was linked to direct effects: medical costs, overtime for some workers, and lost wages for others. The remaining 80 percent came from “aversion behavior,” i.e., not going to those places you normally would, not spending money you normally would spend. When lockdowns, quarantines, and shelter-in-place orders go out, aversion becomes mandatory. When politicians equivocate about whether to take science seriously, aversion becomes common sense.

Philadelphia’s Yellow Fever outbreak in 1793 caused the deaths of 5,000 people, 10 percent of the city’s population at the time. Citizens quickly established social distancing; contemporary accounts tell of people refusing handshakes and crossing the street when passing a home where they thought someone was ill. It wasn’t until 1899 that US Army physician Walter Reed discovered that the disease was transmitted by mosquitoes, not people. The extreme social distancing of the 20,000 people who fled the city, and the blockades other cities imposed on people and goods from Philadelphia, did less intense but far broader harm than the illness and death in the city.

The same early and comprehensive social-isolation policies and behaviors that benefit public health also erode economies. Boccaccio’s carousers were an affront to propriety and public health, but were they curfewed, it would have been an affront to innkeepers and wine merchants. It’s a classic wicked problem.

We could design restroom configurations that encouraged handwashing, social-segregation restaurants, and put a negative-pressure quarantine room in every new home. We could equip every space with a niche for sanitary wipes and go to town on return vents (that would at least make us popular with HVAC contractors). A germaphobe in normal times, I’d welcome a miniboom in furniture, fixtures, and doors that can be manipulated without touching. Some old friends could be poised for a comeback: revolving doors, private offices, and grand staircases that tempt users away from crowding into elevators at definitely less-than-six-feet distances.

But physical design is usually undermined by economic imperatives when the source of panic goes away. Think of the plan of Philadelphia, a “greene country towne” on an orderly grid stretching symmetrically between two rivers. It was drawn in 1682 with London’s Great Plague of 1665 and its Great Fire of 1666 in mind. In short order, Philadelphians broke through the grid to the northwest and southwest, and their city metastasized ad hoc up and down the Delaware riverfront instead of progressing westward into the preplatted city. Speculators subdivided up the capacious, regular blocks into warrens of narrow lanes for tiny houses.

So rather than designing new spatial configurations, it might be more productive to design new behaviors, new interactions, and new expectations for urban life. “Cough into your hand,” we were told as kids, but we tell ours to hack into the crook of their elbows. That was an act of design. Someone, considering the touching potential and range of motion of our arms, worked out that the “Dracula cough” provided enough hygiene benefits to overcome its awkwardness.

Inserting masks and gloves into the picture will help—at least, that is what the CDC is saying at the moment. But it is not design. Photos taken during the influenza pandemic of 1918 (still the deadliest single disaster in world history) show citizens riding streetcars and watching baseball games with the four-fold buttercloth masks that had been mandated by cities. Even modern protectives lend a sense of potentially false security; most of us don’t have the knowledge and discipline to use them at 100 percent effectiveness. And we don’t have enough to go around anyway.

Compared to 1918, or even the SARS scare of 2003, there’s much more we can do on our phones and computers. Still the gap between technology’s ubiquity and its limits reveals how much human productivity depends on putting people into direct contact. Can we redesign quotidian routines that maintain sociability at a distance, that dim the lights of civic life without switching them all off?

A library where you have a seven-minute slot to browse alone. A humble collapsible table that becomes the drop-off/pickup interface between a café and its customers. Before you close the park, why not post a guard (because someone needs that job) and a directive to keep apart? Already offices are experimenting with employees coming in on alternating days to stay open at reduced density; it would take only an overlay on a plan to define who occupies which areas and when. The dimension strings can jump out of these drawings and into real space to demonstrate what 6 feet feels like. To resist the human instinct to draw closer to people when we talk to them, and to overcome the muffling of a mask, signage and nonverbal wayfinding assume new importance. Public transit has to keep running, so creating new relief for choke points of crowding could save lives.

We need but a mean trickle of activity to keep our civic and economic channels running, and faster to fill once the worst is passed, like the trickle of running water that keeps a pipe from icing up. A trickle of consumer spending translates into a trickle of paychecks to employees. Our cities are passing through an uncertain and tense time, but they need not be Sarajevos. A trickle of people living publicly tamps down the fear.