As the spark that lit the San Diego Blackout hurtled full-throttle across the electrical landscape, various lines, substations and generators tripped off-line, throwing the system out of balance. Grid operators tried to extinguish the flare-ups by cranking up peak generators, but they weren't quick enough. Meanwhile, the various collapses in the system forced virtually all of San Diego's electricity onto one set of power lines, running from San Onofre Nuclear Generating Station southward into the city. At 3:38:21 p.m., the lines tripped, and San Onofre's reactors shut down. Milliseconds later, all of Southern California was without power.

The ensuing 12 hours of darkness cost the city and its businesses an estimated $100 million for everything from spoiled food to lost productivity to government overtime. Officials at San Diego Gas & Electric quickly used the failure to their political advantage, speculating that if the Sunrise Powerlink -- a controversial power line bringing solar and wind power 120 miles from the Imperial Valley west to San Diego -- had been in operation, it might have prevented the outage or helped facilitate a quicker recovery. (The Powerlink started carrying wind power from the also-controversial Ocotillo wind farm this January.)

It took regulators six months to sort through what had happened, and in spring 2012, they released a report detailing the to-the-millisecond timeline, and assigning blame for the outage on poor communication, bad procedures and sloppy planning. Grid-oriented greens were at least somewhat validated: Had better "real-time situational awareness," or a smarter grid, been in place, the whole thing might have been avoided, according to the report. A good energy imbalance market might have given grid operators quicker access to backup, alleviating some of the pain.

One thing is certain: More blackouts will occur. California grid operators worry they could come this summer: San Onofre has been offline for repairs (unrelated to the 2011 outage) since January 2012, and no one can be certain when it will be back in service.

But perhaps the biggest, most insidious threat is our warming climate, which is already attacking the grid on many a front, according to the report, Global Climate Change Impacts in the United States. Weather-related outages have increased tenfold in the last two decades, and it's only bound to get worse. Hotter days mean bigger peak loads; higher loads and higher temperatures strain power lines, causing them to lose more of the electricity flowing through them and to sag into vegetation: The West's biggest outage thus far put some 7.5 million people across seven states into the dark when, during a triple-digit heat wave, a line near Portland sagged into a filbert tree, sparking a cascading outage. And of course, heat and drought exacerbate wildfires, which can take out major power lines as happened in 2007 in San Diego, as well as diminish hydroelectric capacity from reservoirs. Meanwhile, it's our fossil-fueled electricity system that emits the largest share -- some 40 percent -- of greenhouse gases.

We may have reached the point at which adaptation is the best approach. While shopping malls across San Diego shut down entirely, and Hooters turned away customers, some bars fired up generators to keep the lights on, and the customers poured in. An Albertson's grocery store kept the coolers humming with a natural gas-powered fuel cell and had a banner day. They had all effectively thumbed their noses at the 20th century's finest engineering achievement and instead gone back in time to the days of the ultra-local Ames micro-grid. By doing so, they breezed right through what so many others experienced as a catastrophe.

On Sept. 8, 2011, Sasha Seyb, a freelance decorative artisan in her late 30s, who has lived in downtown San Diego for several years, was driving from work on the coast to her home when the outage hit. She first noticed that streetlights were blinking, and then realized that neither her radio nor her cellphone worked. Her first reaction was to panic, thinking some sort of major catastrophe had hit. But after she got home, and the news circulated that it was merely a technical glitch way over in Arizona, she and her whole neighborhood simply breathed a sigh of relief.

"Everybody was outside, the kids were all eating ice cream, adults were drinking their beer and grilling steaks," she says. "It was a giant block-party barbecue. It was a really neat vibe, a nice feeling. And that night, you could actually see the stars for once."

Jonathan Thompson is a senior editor at High Country News. He pursues his unhealthy obsession with esoteric topics out of Durango, Colorado.

This coverage is supported by contributors to the High Country News Enterprise Journalism Fund.