The father of a 2-year-old who died in a weekend ATV crash said he looked down to check a text message while the boy somehow pushed the throttle, prompting the dad to fall off the vehicle before the toddler sustained fatal injuries.

Jackson Moore, 2, of Eureka was riding on a slow-moving all-terrain vehicle that his father, Nicholas Moore, 29, was driving Saturday through a wooded area of Franklin County.

Moore told the St. Louis Post-Dispatch in Monday's edition that he had his son in his lap, and was traveling at a speed that allowed his brother Tony, a paramedic, to walk alongside them. The father said he looked at his cell phone and then tumbled to the ground, apparently when the child hit the throttle before the ATV ran into a tree.

"He was out of sight and I heard the boom," said Nicholas Moore. "I don't know how he held on." The child was not wearing a helmet.

Tony Moore performed CPR, but the boy was pronounced dead a short time later at St. John's Mercy Hospital in Washington.

Nicholas Moore also said his son had fired a .22-caliber rifle for the first time at a friend's farm earlier in the day.

Moore said he questioned his decision to allow his son on the ATV, and to be distracted by his phone, but he said he had been being careful.

Nicholas Moore, a single father who is an electrician, loved spending time with his boy, who was his only child.

Sgt. Julie Scerine said the Missouri State Highway Patrol continued to investigate the crash Monday, but that additional details were not available. A funeral home in Eureka said funeral arrangements were still pending.

State law prohibits riders younger than 16 from operating an ATV unless supervised by a parent or guardian, or if they are driving on private property owned by a parent or guardian.

Jackson's grandmother, Gail Moore, 54, called the crash a freak accident. "Nobody did anything crazy," she said.