CC, it depends on the cool down rate. I've only seen the big die offs when a real hard freeze hits, and it rapidly drops the water temp below 55 degrees. A small dip in temps and then a warmup makes them lethargic, and they're sitting ducks for LMB.
In 2016, we purchased or grew out close to 400#'s of tilapia, and if I remember correctly, I only found 4-5 tilapia that were in distress, and they were all over 11". They were all gone the next morning. Raccoons, buzzards, turtles, and GBH all seem to get in on the feeding action.
My comments refer to Mozambique tilapia, not Blues.
