Bridge (2017) online

In a small town in southern Missouri, two brothers share an ordinary summer afternoon. As they walk to the river, the older brother shares the news of his departure to join the army. The little brother is understandably shaken, but soon decides that he can salvage the afternoon by convincing the older brother to grab their gun and shoot frogs. As they return to the bridge, the older brother trips and the gun goes fires accidentally, hitting the older brother in the head. The younger brother runs off for help