Plunker,

Like with most everything, hindsight is so much better than foresight. While it always seems after the fact that most hatchery fish kills are avoidable, people who devote their professional careers to hatchery system work are among the most surprised to discover that the latest fail-safe system wasn't. It's been my observation that as long as there have been, and as long as there are, hatcheries, there will be periodic fish kills. As soon as the latest problem is corrected, another flaw in the system reveals itself. I think the result is that major facility fish kills are less common than they once were, reducing the frequency to zero isn't likely.

Sincerely,

Salmo g.