hmm...
google and wiki lied to me!
They insist the Polo Grounds were at 110th street just north of Central Park. Oh.. damn! There was a 2nd and 3rd and 4th Polo Grounds!
That wiki page included this:
Deaths at the Polo Grounds
On August 16, 1920, Cleveland Indians shortstop Ray Chapman was hit in the head by a pitch thrown by the Yankees' Carl Mays. At the time, batters did not wear helmets. Chapman died 12 hours after he was hit, at 4:30 a.m. on August 17. He remains the only player to die from an injury sustained in a Major League Baseball game.
On July 4, 1950, Bernard Doyle, a resident of Fairview, New Jersey, in his 50s, originally from Dublin, Ireland, was struck and killed by a stray bullet while in his seat at the Polo Grounds. Doyle had brought a neighbor's son with him to see a doubleheader between the Dodgers and the Giants. Doyle was killed about an hour prior to the start of the first game. A 14-year-old boy later confessed to having shot a .45 caliber pistol into the air from his rooftop at 515 Edgecombe Avenue, located 1,120 feet (340 m) from where Doyle was seated.