The tragedy happened at an unofficial block party in the 500 block of South San Carlo Avenue as a number of illegal fireworks were being shot off from a mortar-style tube, according to the San Bernardino Police Department.
One of the fireworks malfunctioned and hit the 8-year-old boy in the upper body.
The boy was taken to a hospital to be treated, but he later succumbed to his injuries.
Police have not released details on the boy's identity and say they are actively investigating the incident.
Anyone with information about the case can contact Sgt. Hysen at (909) 384-5659 and by email at email@example.com.