Hobby/recreational UAS pilot reported they believe an object struck the UAS during flight causing a crash.

Narrative

Written on Day 0 at XA:58. I was flying my Potensic Dreamer Pro recreationally at Location A; located in ZZZ. I was flying over the waters of [the] Lake. At one point during my flight; I decided to bring the drone in close to me to prepare for a diagonal; backwards ascent with the subject being me in the center of the frame. I started to do the backwards; manual ascent; at an altitude of about 20 feet AGL (MSL altitude is almost the same since the Park elevation is just a few feet above the water of [the] Lake) with the drone facing me but flying upwards and away from me (basically doing a dronie). Out of nowhere one of the propellers snapped in half and the drone fell into the water below; next to a path/stretch of rocks. I went to go retrieve it and found it to be completely destroyed and useless. On my way back to my car; two guys in their gray/silver cars told me they believe they saw passenger(s) in a pickup truck at the back of the parking lot shoot it down with likely either an airsoft gun or BB gun. It makes sense; because I was flying completely unobstructed with no other UAS in the area and no bird or birds flew into my drone. I was flying in a completely open space and did my pre-flight check; knowing I did everything correctly and screwed on the propellers correctly. All of that leaves to believe it was shot down because the propeller just doesn't snap in half like that unless the drone flew into an object; or something flew into it; which both did not happen. I also did not activate the emergency propeller stop function as the drone doesn't even come with that feature. Also; just before takeoff; I heard someone say 'what if we shot down the drone?' And they were right near the pickup truck. I thought nothing of it because I thought they were joking and being sarcastic. Bad aeronautical decision making (ADM) on my part; lesson learned. This incident took place on Day 1 during civil twilight. I had the aircraft registered under part 107 with the expiration date being Day 2. I recently canceled the registration with the reason being 'damaged' as of yesterday; Day 1. I contacted my instructor from an online organization on what to do. He said to report it here as a safety event. That was not one of the options up top so I chose 'uncontrolled descent from the sky' and 'other: apparent gunshot at drone'. I did not call law enforcement and I am not sure if I need to report this to the NTSB or FAA or neither; if no report needs to be made at all.