My 5 year old brother in law accidentally fired my rifle

My brother in law(5) was staying with us for the weekend and us having no where to put my rifle in our spare room, I just leaned it against a small table. He and my wife (his sister) were sitting on the bed playing on her phone when he got up and came over to the rifle, cocked it and fired it into the ground. Thankfully it wasn't pointed towards them when he pulled the trigger. The bullet went through the floor and into the room below. Thankfully no one was in the apartment below and it didn't hit anyone. I'm just extremely grateful that nothing worse happened and I now keep my rifle locked in my truck.