CBS 3 in Philadelphia reports:
A friend of Tavin's, who was also involved in the playful snowball fight, said the shooting happened after a wayward snowball accidentally struck a nearby neighbor.
Police said the adult male became enraged and left the scene, returning moments later with a gun.
Witnesses say Tavin's effort to apologize to the man went unnoticed and the man pulled out a gun and began firing.
Family and friends celebrating Tavin's birthday heard gunshots and found him bleeding on the front porch.
"We ran outside and saw Tavin laying on the step," said the victim's friend Mercedes Lebron. "When I picked him up, smoke stared coming out of his head … He still was breathing and we told him keep breathing, calm down."
Tavin was rushed to Temple University hospital where he was taken off life-support. At 11:30 a.m. Monday, with his family by his side, Tavin passed away.