Not sure of the terrain but did she slip, tumble, fall down go boom and roll into the drink ?
The levees typically don’t have a lot of rocks. The running and biking paths are generally wide, flat, and well maintained. You’d pretty much have to intentionally go into the water which she did the previous day. It sounds like she might have had a medical issue based on her bizarre behavior the day before, but there is no explanation of her blunt force injuries, her manner of death, or the closing of the case by the coroner’s office.