My colleague Melissa Lott presciently today in this very space recalled the enormous India blackouts of 2012 and discussed new algorithms for addressing similar events in the future.

Cue thunder, offstage: Toronto got almost 5 inches of rain on the night of July 8, washing out its downtown to an unprecedented scale. And naturally, after a storm of that magnitude, many people went without power -- some 300,000, in fact, during the storm's worst, with 20,000 without power afterwards.

Then it became clear that with one of the Hydro One power stations providing power to the Toronto Hydro electrical grid under 20 feet of water, the power supply was, in the words of Toronto Mayor Rob Ford, "hanging by a thread." The first call was for customers to back off power demand via load-shedding -- asking customers to turn off everything they could, throttle back on air conditioning, keep the refrigerator doors shut, and so on. Most utilities now offer cost savings by asking commercial and industrial customers to willingly allow their electric utilities to manage their load by, say, allowing air conditioning thermostat settings to rise when power consumption is high to avoid overextending the grid. Many offer residential customers the same benefit. And the premise of the Smart Grid and the many home management programs already available is to load shift -- peak energy demands come around breakfast time and in early evening hours, so if you program your dishwasher and wash machine to do their jobs at 2 a.m., you do a favor for your utility and can reap economic rewards for doing it. ON the other hand, nature respects no such agreements -- when five inches of rain floods your generating station, you end up hanging by a thread so slender that Toronto Hydro had to implement the familiar third-world strategy of rolling blackouts, in which the power just goes out for certain areas, and the only benefit darkened customers get is -- hopefully -- a bit of notice.

CBC journalist Kerry Wall was on the case, though. Before she left work, she created a Google Map of the blackout areas -- and left it updateable by readers. So Toronto readers could check whether their neighborhoods have power before they went home -- or could make other arrangements if they were.

Microgrid apologists will find in this support for the neighborhood-scale electrical systems they envision, though the idea only comforts you if it's not your neighborhood under 20 feet of water; traditional grid supporters will tout the speed with which Toronto Hydro will be able to get the entire grid back up and running. It's hard to see a storm like this supporting anybody's position except the realists'. When a great big storm comes, sometimes the lights go out.