A horrible crime, committed by youth with little thought of the consequences. How are your koi protected?  This pond appears to located in a very accessible place with no fencing to protect them, however it is in a gated community.  Are your koi protected from stupid people? 
 
"OREM, Utah (ABC4) – A Utah County family is grappling with the loss of their pets, all at the hands of teens who reportedly dumped dish soap in their pond, killing hundreds of koi fish.  Olivia Burton says her father was devastated early Saturday morning when he got to his pond and saw the aftermath of what appeared to be some kind of prank."
 
https://localtoday.news/ut/teens-pour-dish-soap-into-koi-pond-killing-hu...
 
YouTube: https://www.youtube.com/watch?v=Ej9EPB6n92w  (security camera at the home)