Federal authorities from Homeland Security and FEMA are running nuclear response drills called "Operation Gotham Shield" in which the scenario is an improvised nuclear device going off on the west side of the Lincoln Tunnel.
The drills, at MetLife Stadium in northern New Jersey, simulate a 10,000-ton improvised nuclear device going off, with authorities practicing how to evacuate and treat victims of a potential nuclear attack in the New York City area.
New York, New Jersey and Connecticut emergency management teams are also participating.
Similar-type drills are taking place in Albany and Washington, D.C.
The multi-day drills at MetLife Stadium, which began on Monday, are not in response to any current events, including possible threats from North Korea, federal authorities said.