Does everyone have their generators ready? :-) http://www.innerx.net/personal/tsmith/13Mar89.html
On 13 March 1989, the voltage of Quebec's power grid began to fluctuate alarmingly. Seconds later, the lights went out across the entire province. Some 6 million people were without electricity for nine hours. Within two days, NASA had lost track of some of its spacecraft and the northern lights were glowing in the sky south of London. As described in the 3 February 1996 issue of The New Scientist, these events had the same cause - a monumental Solar Storm, the fiercest for 30 years >- the electrical grid acts as a big radio antenna and circuit breakers may trip.
