I'm surprised the remaining two are surviving, but it makes me think two things happened...1) I left the lights on when I should have turned them off while we went through the heat wave and...I inadvertently let the roots dry out with transferring the plants indoors. I also should have turned my fans down in the grow tent, as they ended up circulating really hot air which also dried the plants further, faster. Live and learn. I feel stupid as this did not have to happen.