SAN ANTONIO -

A 51-year-old grandfather was charged in connection with a fire that killed his 2-year-old grandson.

Joel Soto, 51, is charged with felony arson of a vehicle.

Soto told investigators his truck was having trouble so he pulled over near Rogers Road and Mt. Evans to examine it.

He claims he began working on the carburetor when a flash fire ignited and knocked him to the ground.

According to the arrest affidavit, Soto said the injuries he sustained kept him from trying to rescue his 2-year-old grandson, Jeremy Alonzo Soto, who was trapped inside.

The child was pronounced dead at the scene.

Soto told investigators a full container of gasoline was behind the passenger seat, according to the affidavit.

The document also states that Soto's injuries were "inconsistent with his explanation of events."

But SAFD arson investigators found no evidence of a gas container upon their examination of the truck days later.

The police report of the incident states the fire might have started inside the truck and not in the engine area.

Both SAPD and SAFD are investigating.

Jeremy Alonzo Soto