The Arpanet outage of Oct 27, 1980 pretty much took the whole thing down (slightly before the name changed to Internet). See RFC 789. A single flakey IMP announ

The Arpanet outage of Oct 27, 1980 pretty much took the whole thing down (slightly before the name changed to Internet). See RFC 789. A single flakey IMP announced it was zero hops from all others, so all traffic went to it.