BRAZORIA COUNTY, Texas -

Two children are dead after a disabled truck they were helping to push was hit by another vehicle.

It happened around 11:30 p.m. Friday night on County Road 144 near County Road 712C in Brazoria County.

Investigators said the Barajas family was coming home from a family dinner when their truck ran out of gas. David Barajas II, 12, and his brother Caleb, 11, got out to help their father, David Barajas, push the pickup home. Detectives said they were almost to their driveway when tragedy struck.

"Another vehicle came from behind and collided with that vehicle from the rear," said Dominick Sanders, Criminal Investigator with the Brazoria County Sheriff's Office.

David II was killed, and Caleb was rushed to the hospital where he later died, investigators said.

Officials said the father was injured in the crash as well. He was taken to the hospital with non-life threatening injuries.

In a strange twist, investigators on the scene said the driver of the vehicle that hit the truck had a gunshot wound to his head. He was flown to the hospital where he later died, officials said.

Investigators said they'd spent the morning inside the Barajas home executing a search warrant.

"We're just trying to locate any evidence that may help us solve this tragic incident," said Sanders.

Detectives said it's too soon in the investigation to know how the driver ended up shot, or whether the shooting happened before or after the accident.