the death of their mother, Mary, by a demon, Azazel, and their father, John, becoming a hunter to seek revenge and raise them in a life dedicated to hunting supernatural creatures to then my father john winchester he died of cancer to then Mary Winchester was revived on October 13, 2016 hmmm i see She was brought back to life by Amara. She was also resurrected again oh i think she dead we are sad moment forever