If everyone stops using it or if in some way becomes wothless, these are the two situations I think of that could make bitcoin die. But I don't know what could cause something like this, people get used to bitcoin and all benefits that it gives and demand is geting biger all the time.
It is so very impossible that everyone would stop using bitcoin for becoming worthless there is a less chance that bitcoin will go down because as of now many people are now using bitcoin to earn money and future purposes. Maybe the only way that bitcoin would die is because of the government if anyone will start bitcoin as payment for illegal activities maybe the government will declare bitcoin as illegal too and they will shutdown bitcoin.