New York City near the city, which would be more likely to cause damage to taller structures from an earthquake in the vicinity of the city. is often referred to collectively as the five boroughs, and in turn, there are throughout the boroughs, many with a definable history and character to call their own. If the boroughs were each independent cities, four of the boroughs (Brooklyn, Queens, Manhattan, and the Bronx) would be among the ten most populous cities in the United States (Staten island would be ranked 37th) ; these same boroughs are coterminous with the four most densely populated counties in
Staten Island Tunnel funded by the city, the tunnel was expected to help expand the then-sparsely populated borough in a similar manner to the population and development explosions seen in Brooklyn and the Bronx. Under the Dual Contracts, three routes were proposed—two to Brooklyn and one to Manhattan—which would connect the Staten Island Railway's rapid transit service (SIRT) to existing subway lines. The Manhattan proposal, often called the "direct route," would have connected with the Interborough Rapid Transit Company (IRT)'s lines under Battery Park, near the current Brooklyn–Battery Tunnel. "Direct Route A" would have utilized a five-section tunnel under the New York Harbor,