If bitcoin die I dont think altcoins die. Yes some altcoins for sure die because it deoends ti the bitcoin price but they have altcoins deoends to the dollars price and for sure it will still a live what ever happens in bitcoin. But as of now bitcoin will not die and it will live in the online world in the next few years and bitcoin will become more powerful and popular so the price will continue to increase.
People get it wrong whenever they say that an altcoins will take over Bitcoin. I dont really think thats true. If Bitcoin ends today, it will affect other crypto currencies heavily, and 90% of them all will close down/fall. Bitcoin is the road builder and rules the block chain.
Ethereum could take the reigns of bitcoin and be the new bitcoin easily. And with cheaper transfer fees. And with all the other cool stuff that Ethereum does

#ETHisKING
So i believe if bitcoin dies for any reason except the one that crypto currencies get banned by the government or other stuff Ethereum could take over.
There is no possibility of bitcoin die and if it will happen unfortunately altcoin will die also because bitcoin introduces the trend of digital currency and still people have faith in it and there is no chance of this theory bitcoin is giving profit to the peoples and no other altcoin can replace it and it will never die because of its ever green profit.