Just look at the first image on the Wikipedia page, showing the extent of the blackout. This is far smaller than the footprint of the eastern interconnect. The

Just look at the first image on the Wikipedia page, showing the extent of the blackout. This is far smaller than the footprint of the eastern interconnect. The control software at the time made some simplifying approximations which left the grid vulnerable to problems cascading between operators. I do not think they have quite the same problem anymore. https://en.m.wikipedia.org/wiki/Northeast_blackout_of_2003 https://en.m.wikipedia.org/wiki/Northeast_blackout_of_2003