Police withheld the name of the fatality and the injured boy.
Police Lt. Col. Necerato Sabando Jr., Hinigaran police chief, identified the two other injured victims as Klana Joy Parreno, 18, and Myra Bacolinao, 24, residents of Barangay Gargato.
Sabando said the victims were packing dried fish in the storage room when Jumo Potueco, 36, an employee, saw the keys and drove the truck.
Potueco accelerated the truck and crashed into the storage room where the victims were working, Sabando said.
The fatality who was just helping the two injured employees was ran over and the two women and the boy sustained minor injuries, Sabando said.
The fatality was taken to a hospital where she was declared dead.
The owner or driver of the truck was not around when the incident happened.
Potueco was taken to the Hinigaran Municipal Police Station and will face charges for reckless imprudence resulting in homicide, multiple physical injuries, and damage to properties.