An event capable of destroying our civilization has already happened, but in 1859 it didn't have much effect then. Basically it disrupted telegraph systems and created auroras as far south as Cuba, bright enough to wake up miners in Colorado or read a newspaper at midnight.
When it happens again, it's likely that auroras and firelight will be the only lights you'll see. .
Richard Fisher, head of NASA's Heliophysics Division, explains what it's all about:
"The sun is waking up from a deep slumber, and in the next few years we expect to see much higher levels of solar activity. At the same time, our technological society has developed an unprecedented sensitivity to solar storms. The intersection of these two issues is what we're getting together to discuss."