With many commuters avoiding Manhattan, the crowd at Grand Central Terminal was eerily sparse Tuesday afternoon, while major construction projects nearby continued. At One Vanderbilt, a massive office tower being built just west of the terminal, clanking metal and drills resounded through streets that were quiet save for the occasional car horn or siren.

A few blocks north, workers were toiling away at JPMorgan Chase’s new tower. One guarded the site sporting a white helmet and a giant black face mask.

In the Hudson Yards area, about 500 crew members were working on the Javits Convention Center. That could change soon, with local officials considering stricter rules that would require most New Yorkers to stay home.

If construction projects in the city are halted, the economic repercussions could be devastating. There are currently more than 6,800 active construction sites across the city, employing tens of thousands of workers.

Shutting down the projects could bankrupt construction firms and lead to massive layoffs, issues that other industries are contending with as the virus roils the U.S. economy.

“The economic impact of what happens to projects that aren’t moving is devastating” said Carlo Scissura, president and chief executive of the New York Building Congress. “There are so many things that are critical to the lifeblood of the residents of New York. You can’t just say Shut down everything.”