Since the first line connected lower Manhattan to Harlem in 1904, New York’s subway has never ceased running. There were brief blips of interruption after the 9/11 attacks and in the last decade for hurricanes and blizzards, but for more than 115 years the rumbling on the rails has kept the click-clack heartbeat of New York. It’s a second, tunneled city that, like the skyward metropolis above, never sleeps.

Last week, for the first time, the trains stopped running in a planned shutdown. Between the hours of 1 and 5 a.m., the subways and New York’s 472 stations began closing for a nightly cleaning to disinfect trains. It’s a humbling concession for a swaggering, all-night town that, as much as anything, shows how the coronavirus pandemic has seized the gears of New York, one of the world’s hardest hit cities.

Except for commuters fleeing to the suburbs, the entire concept of “last train” is anathema in New York. London, sure. Boston, of course. Even Tokyo. But not in New York. Through the night, trains have always shuttled early-morning workers and late-night revelers. A four-hour shutdown may not seem like a drastic change given all the transformations wrought by the pandemic. But in New York, it means a tear in the fabric of the city.

“Without the subway, New York does not work. People are saying now, ‘What happens if people drive after the epidemic has passed?’ Well, they can’t do it. If all the people who wanted to drive in New York drove, you’d have to pave over Long Island to park all of the cars,” says Kenneth T. Jackson, a history professor at Columbia and author of “Empire City: New York Through the Centuries.” “It’s more important than the public schools. It’s more important than anything.”