Dirt Bike Track Cakes Dirt-bike Track - Should Their Insurance Be Notified?

Dirt-bike track - should their insurance be notified? - dirt bike track cakes

My neighbors found a new home cycling dirt on their property. Children (5) is mounted on the track. Shall I tell you his insurance company (I know it). I hate to see these kids get hurt. Should I be held responsible or should I wait until the inevitable happens?