SANTAQUIN, Utah (KTVX/KUCW) – A Utah man was killed and his mother flown to the hospital after the man’s son accidentally changed gears of a truck they were using to do yard work Saturday.

Santaquin Police responded to the incident in Santaquin’s Summit Ridge community shortly after 4:30 p.m.

A 23-year-old father and his 47-year-old mother were reportedly cleaning up the home’s yard at the time, loading large rocks into the bed of the truck, which was parked on a slope toward the yard.

Police say while they were loading the truck, the man’s child climbed into the vehicle and pulled on the gear shift, which was reportedly broken and able to move despite the truck’s engine being off.

After the gears changed, police say the truck rolled backwards onto the boy’s father and grandmother.

The grandmother was reportedly flown to the hospital with serious injuries. Officers performed life-saving measures on the boy’s father, but he was pronounced dead at the scene.

The identities of the victims are not being released at this time.

No further information is currently available.