RedactedNarrative: On July 29,2018 at approximately 12:45pm a PWC (KY0526NK) owned by operator was riding slightly upstream from the Cheatham Dam Beach swimming area.  His required engine kill switch was not attached properly to his person and the throttle did not return to idle after he fell off.  
  
  This caused the PWC to take off at approximately 40mph towards Cheatham Dam Beach swimming area.  Witness observed a non-driven PWC heading towards the swimming area and tried to warn swimmers. Due to its speed four swimmers near the swimming areas outer yellow perimeter did not have enough time to react to the oncoming vessel.  The PWC physically struck 4 female swimmers.  
  
  Operators blood was taken at seen and on 12/5/18 TBI results Alcohol detection was negative.  Drug screen showed Amphetamine at 0.09ug/ml and Norbuprenorphine at 1 ng/ml.