Normally I’m a “glass half empty” guy. But reading this fascinating WSJ piece about how a single soccer match helped seed Italy’s catastrophe makes it easy to look at the glass half full, even at a moment as grim as we’re in.

As bad as things are right now, consider how much wider the contagion might be if St. Patrick’s Day parades and pub crawls had been held as scheduled. New York City’s parade was canceled less than a week before the big day. So were Boston’s and Chicago’s. Imagine millions of people across the country shoulder to shoulder in the streets and in bars, passing this plague around because it hadn’t yet fully landed on the public’s radar. What would hospitals in major cities look like now?

Imagine the NCAA holding March Madness as scheduled, with tens of thousands of people packing into arenas over three weeks. Imagine full houses at baseball stadiums, with 40-50,000 plus in attendance, on MLB’s opening day. Or, beyond sports, imagine if South By Southwest had been held in Austin as scheduled instead of being canceled a week out. More than 400,000 people from around the country attended SXSW events in 2017.

In Italy, it took one match with a crowd of 40,000 to light the fuse on an epidemic that’s killed more than 13,000 people. Atalanta, a team from Italy’s stricken northern region of Bergamo, played Valencia in a Champions League match on February 19, a day when there were three — three — confirmed COVID-19 cases in Italy. Local interest was so intense that the match was moved to Milan to accommodate more spectators. Atalanta won and everyone went back home to Bergamo. Then all hell broke loose.

“Two weeks after Feb. 19, there was an incredible explosion of cases,” said Dr. Francesco Le Foche, an immunologist in charge of infectious disease at Policlinico Umberto I in Rome. “The match played a huge role in disseminating coronavirus throughout Lombardy and in Bergamo in particular.”

Atalanta supporter Luca Brignoli, 57, thinks back to his subway ride to the San Siro from downtown Milan, bodies jammed against the door. He remembers milling around the piazza in front of the stadium, where fans from both sides mixed and drank and snacked from food trucks. He wonders how many people might have coughed or sneezed while navigating the stadium’s turnstiles and narrow passages…

“We underestimated this infection,” said Martina Cambiaghi, Lombardy’s minister for sport—and one of the 40,000 in the San Siro. “After the match, fans were in pubs, in bars, in restaurants in Milan, not only in Bergamo. This event was the great accelerator. But really we didn’t know that it was a problem.”

Less than three weeks after the match, Bergamo alone had a thousand cases of coronavirus. Today they have 8,800, the single hottest hot spot in the country apart from — you guessed it — Milan.

It could have been worse here. But of course, it could have been better too. (Glass half empty!) COVID-19 arrived too late to stop Mardi Gras, a key reason why New Orleans looks like the next U.S. epicenter for the disease. NBA and college basketball games, as well as NHL hockey games, continued in early March too despite the fact that the virus was already taking off in Italy and showing us what lay in store for America soon.

There’s a glass-half-full view of that too, though. Apart from March Madness, the virus arrived at a low-stakes moment for American sports. The NBA and NHL playoffs hadn’t begun yet. If they had, the two leagues might have dawdled about canceling games. Baseball season was still weeks away and football season, both pro and college, was over. If in fact the virus is more active in cooler weather, mid-February to mid-March is the most optimal time it could have erupted here to minimize the number of sports spectators infecting each other at games. In any other period from October through June, there’d be at least three pro sports going.

If 40,000 in a stadium in Milan was this dangerous, imagine 100,000 packing into the Big House in Michigan for a couple of weekends in late October and early November while the virus was beginning to spread. And then dispersing across the state and the country to carry the virus home during Thanksgiving break.

It could have been worse. But, having been spared the worst-case scenario, let’s not do stupid things going forward to enable smaller gatherings that’ll spread the virus anyway. Please?