Well, no electricity, and no internet connection would kill BTC for sure! You wouldn't be able to make any transactions without these.
Other issue can be all the countries in the world ban BTC, but this will not restrict it's circulation, as no internet connection do!
In other words, bitcoins can not be killed by anyone because the electricity and the internet are not lost. Depending on whether there is a widespread war, money and bitcoins will no longer be profitable. Really bitcoins can no longer be prevented and it really happens that the world must be changing and with each passing moment there are new ones that will expose the future of people living in the future