Investigators said Aaliyah Boyer of Manheim, Pa., was hit by a bullet that went into her brainstem, WCAU-TV in Philadelphia reported. She and her mother, Crystal Blackburn, were spending New Year's with relatives in Elkton, Md.
Aaliyah was hospitalized at A.I. DuPont Hospital for Children in Newark, Del., where doctors said Wednesday night she was brain dead, WPVI-TV in Philadelphia said. She died Thursday morning.
Blackburn told WPVI that Aaliyah's organs, including her heart, were donated to help other children.
"I pray for those kids that they make it, that they live long happy lives with Aaliyah's gift," Blackburn said.
Ashley Rice, Aaliyah's aunt, told WBAL-TV in Baltimore, no one realized the little girl had been shot until police arrived, believing instead she had fallen and hit her head. She said the family did not hear the gunshots over the sound of the fireworks.
Police were canvassing the neighborhood, checking guns. Firing into the air is a crime in Maryland.
"To fire a gun for a celebratory reason is just a terrible, horrible idea and incidents like this can happen," Cecil County Sheriff's Lt. Michael Holmes said.