by KYW's Brad Segall
State and county fire officials continue to investigate Saturday night's deadly accident that occurred near the end of Quakertown, Pa.’s Fourth of July fireworks celebration.
An autopsy on 19-year-old David Walker shows the preliminary cause of death was neck trauma, and the Bucks County coroner has ruled the death "accidental."
Fire officials say it appears that an eight-inch mortar exploded while still on the ground, setting off some other nearby fireworks and killing the western Pennsylvania man.
WATCH THE CELLPHONE VIDEO
He was working for Zambelli Fireworks Internationale, which was running the show. The fireworks display was about halfway through when the mortar exploded.
Firefighters immediately administered first aid but Walker was pronounced dead at nearby St. Luke’s Hospital. The show was abruptly halted.
No other injuries were reported.