I lost half my echinacea seedlings. I originally had a dozen, but on a very hot day- eighty or ninety degrees outside- I forgot to open the plant house soon enough, and temps in there soared to over 120°- beyond the range of my thermometer. Seedlings wilted. Half my echinacea died.
Those that didn't kept growing-
And just last week I potted up the eight survivors. They are the few plants left getting babied in the coldframe. Sad to have lost so many, but it will double the numbers of echinacea in my garden, so that's good. The two-year old echinacea should flower this year- they sure have gotten tall.