4-year old boy injured at Mississippi gun show

A 4-year old boy was attending a gun show in Tupelo, Mississippi, when a gun was unintentionally discharged.  The round went through a wall.  The boy was injured by bullet fragments, and a man was injured in the leg.

No charges expected.

From an article:

The child was hit by fragments from a bullet that went through a wall. Also, a man was grazed in the leg in the same accident. 

Tupelo Police say both were treated at North Mississippi Medical Center. Neither suffered life threatening injuries. 

A preliminary investigation indicated it was an accident and no charges are expected. 

The incident is still under investigation.

Why would someone bring a 4-year old to a gun show?