New York City was already on edge about rising gun violence, lawlessness and hate crimes. Then came Tuesday’s attack on a Brooklyn subway, in which a masked suspect detonated a smoke grenade and shot 10 people during the morning rush hour.

As of Tuesday evening the man was still at large, and his motives unknown. But his attack appeared well calculated to unnerve a city in which public safety has become an overriding concern for residents and businesses still struggling to recover from the coronavirus pandemic.

It occurred on the subway, an essential means of transit for the city’s workers but also, increasingly, a warren of homelessness, mental illness and senseless violence. Eric Adams, the city’s new mayor, who began his career as a transit cop, has made tackling crime and safety on the subway in particular one of his top priorities.