I am so sorry as well. My condolensces to you. Please don't be too hard on yourself for not knowing. I am sure that if you knew the dangers you wouldn't have left the halter on. Also, I believe that when it is time for anyone or anything to pass, no matter what one does will not stop it from happening. But for you to post so publicly in order to try to save another horse, that is to be commmended. Your post will save another horse's life somewhere down the line. Thank you.
Everyone, please, no matter the type of fence, or lack there of, please do not leave a halter on a horse without being there to supervise it!
(((Hugs)))