Nowhere in the US will become another New York during the coronavirus pandemic

• New York was uniquely positioned the become the epicenter of the US coronavirus outbreak.
• The city's density, coupled with the early timing of its outbreak, helped fueled the virus' spread.
• Even as states begin to relax lockdown restrictions, no location will face the same circumstances as New York did in March.

Four months after the US recorded its first coronavirus case, New York still has nearly a quarter of US cases and 30% of the country's COVID-19 deaths.

As the state's outbreak winds down and other parts of the country begin to relax lockdown restrictions, attention has shifted to locations that could become new hotspots and to the possibility of new waves of infections. Cases are still rising in Arizona, Illinois, California, and Texas. Illinois' Cook County alone — home to Chicago — has more infections than any other US county, excluding New York City.

But it's highly unlikely that any state's outbreak will rival New York's. The state was a unique victim of density and timing.

"Why New York? Why are we seeing this level of infection?" Gov. Andrew Cuomo said at a press briefing on April 13. "It's very simple. It's about density. It's about the number of people in a small geographic location allowing that virus to spread."

New York City is one of the densest cities in the world, with more than 28,000 people per square mile. Even San Francisco, the second densest city in the US, doesn't come close. Before the pandemic, more than 5 million people in New York City took the subway each day. The city also has the largest school district in the US in terms of enrollment, with nearly 985,000 students.

That means more people in New York were interacting with one another on a daily basis than in any other city, creating more opportunities for the virus to spread.

New York's outbreak also started before any regional lockdowns were in place in the US, and before testing capacity was sufficiently scaled up.

Researchers have suggested that the virus was circulating in the city as early as mid-February. When New York's statewide lockdown went into effect on March 22, there were more than 10,000 recorded cases in New York City alone. And that's only the ones confirmed by tests.

Now that all but five states have implemented some form of lockdown for at least a period of time, the virus is no longer spreading as freely. Even states that have loosened lockdown restrictions aren't reverting to the same behaviors they practiced before the pandemic.

In Florida, restaurants and retail stores are only operating at 50% capacity, social distancing and sanitation measures are required at gyms, and bars and movie theaters remain closed. California is requiring curbside pickup and physical distancing at retail stores — and Gov. Gavin Newsom said the state may not allow spectators at professional sporting events when those games resume this summer.

These lingering restrictions help reduce the potential for a second wave of infections.

Research from Imperial College London suggests that around one-third of coronavirus transmission occurs in households, one-third takes place in schools and workplaces, and one-third happens in the community (at churches, bars, restaurants, grocery stores, and playgrounds). If people continue to work remotely, take food to-go, and social distance in public, the chance of transmission goes down, even once a state is fully "reopen."

The researchers even found that maintaining social distancing for the next two years could be enough to prevent a second wave — a prediction recently echoed by Harvard public-health experts. That means no place will face the same circumstances that New York did in March, as the virus spread silently through the nation's most crowded city.