I don't see any perlite in your medium???...just an aside since aeration and booty is always running through my mind. In regards to the casualty, put that hoe in quarantine until you figure out the problem. Even if it was neglect on your part, most ladies would get bent outta shape under those circumstances. Regardless, no sense is losing all of them...and even if you do, you will gain the knowledge you'll need to succeed next time around. Mistakes are inevitable...how you respond will determine the outcome.