What would happen if the internet dissappeared?

Depending on the interconnectivity a country has, major critical systems would fail and their would be extreme chaos or there would be little effect. For example, an African tribe without electricity will go totally unaffected by internet "disappearing". However, in America the water supply, traffic control, electric grid, weapons systems, etc. all are controlled with the internet and that would cause a lot of chaos and probably a lot of deaths.