Two separate incidents Brooklyn resulted in the death of a 27-year-old man on a Brownsville sidewalk, a nine-year-old girl wounded, and a 13-year-old boy clinging to life. Police are investigating whether the shot that struck the nine-year-old girl in the arm yesterday was related to the shooting that killed Robert Morgan two blocks away in Brownsville. The girl was apparently hit by an errant bullet that crashed through a window in a family's fifth-floor apartment.......