A reminder that koi can live quite a bit of time out of water. I had an unfortunate situation when a young koi leapt from the pond, and in the morning finding it unresponsive (and presumed dead), I placed back in water and gently massaged and moved in the water to reintroduce water running through the mouth. I still have this koi, called Phantom, in my pond today. 
 
"Staff at a British cricket park performed mouth-to-mouth resuscitation on koi carp after vandals entered the grounds overnight and destroyed the holding tank in which the fish were temporarily located,.... 
On the morning of November 3, Colchester Castle Park employees arrived at work to see the fish struggling for air. The employees attempted to resuscitate the larger fish that had not yet suffocated.
 
In all, 45 fish, including valuable koi, were killed from the attack, according to the newspaper, but the quick actions of the employees were able to save some fish."
 
https://www.petage.com/koi-carp-receives-mouth-to-mouth-resuscitation-af...