March 14, 1912, Pittsburgh: The New York Athletic Club and the Chicago Athletic Club played the roughest water polo game on record. Pugilist Joe Choynsky, who once fought James J. Corbett on a barge in San Francisco Bay, was the Chicago coach. After four men had been carried out of the pool unconscious, Pugilist Choynsky hit Joe Ruddy of NYAC on the jaw. Ruddy then hit Choynsky in the eye. A riot started. The Amateur Athletic Union promptly dropped Water Polo from its schedule. For this reason once again, no team was sent to Stockholm 1912 Olympic Games.
Source: http://www.nytimes.com/, A History of USA Water Polo in Olympic Games.