Truck Driver Dies After Helping Children Get Out of School Bus Crash: 'He Was Pretty Much Done'

WSAV3 School bus

A truck driver is dead after helping children get out of school bus that had crashed in Georgia.

The incident occurred on Wednesday around 3:38 p.m. when a Ryder box truck driven Johnathon Grayer, 25, collided with the back of a stopped school bus that was unloading students near Alma in Bacon County, a spokesperson for the Georgia State Patrol tells PEOPLE.

On board the bus at the time of the crash were 10 children, according to authorities.

Grayer immediately jumped out of his vehicle and rushed onto the school bus to help the students inside, Cpl. Shane Copeland told CNN. The driver collapsed after footage from the bus' surveillance camera showed him lifting seats off children who were trapped underneath.

WSAV3 School bus

WSAV3 Truck

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"He must've been running on adrenaline, and his body gave out," Copeland said. "He was pretty much done by that point."

Grayer was transported to the Bacon County Hospital, where he later died, according to the Georgia State Patrol.

The school bus driver, Jerry Sweat, and three students were taken to the same hospital. Three other children were transported to Shands in Jacksonville, Florida, with non life-threatening injuries.

Authorities believe the truck was traveling between 50 and 60 miles per hour when it rear-ended the bus, WTOC reported.

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“We try to do the standard procedures on every crash and treat all crashes equally," Copeland told the outlet. "However emotionally, you can’t help but to think I’ve got three children and you can’t help but to think of your three children on their bus back home and it does make it personal if that makes sense."

Georgia Gov. Brian Kemp tweeted about the fatal accident on Wednesday, writing, "Terrible news out of Alma."

"@GAFirstLady, the girls, and I are praying for the family and loved ones of the truck driver who lost their life and the students who are injured," he wrote.

A follow-up investigation by the GSP Specialized Collision Reconstruction Team (SCRT) is ongoing.