Hell Gate, 1885

It is estimated that the wrecks of over 1,000 ships lie in the Hell Gate. Starting in the 1840s, and continuing for the next 80 years, the Federal government tried various means to remove the rocks and reefs that made the Hell Gate dangerous to shipping. In October 1885, over 300,000 pounds of explosives were detonated, obliterating the once treacherous nine-acre Flood Rock. Nearly 100,000 people gathered on the Manhattan banks of the East River to watch what is said to have been the world’s largest explosion prior to the atomic bomb. Windows rattled as far away as Princeton, New Jersey.

http://www.nycgovparks.org/sub_your_park/historical_signs/hs_historical_sign.php?id=12219