Removal of Hell Gate rocks
地点
In 1851, the U.S. Army Corps of Engineers led by General John Newton began to clear obstacles from Hell Gate, a strait in New York City's East River, with explosives. The operation would last 70 years. On September 24, 1876, the Corps used 50,000 pounds (23,000 kg) of explosives to blast the rocks, which was followed by further blasting.