Yes this was caused by deregulation. The supply side was deregulated state wide, but the demand side was going to be rolled out. It started in San Diego, and there were multiple people selling electricity (utility.com, Green Mountain, as well as SDGE) the established local power companies must sell at a specific rate established by PUC. This rate is determined by the market.
There are two queues of power, one that goes by market price, and an emergency queue (when electricty goes beneath 5%) where the PUC buys at higher rates to insure they never run out of that queue and cause power outages. Meanwhile during deregulation, what happened was that no provision was made for making sure that there was enough supply to create a competitive marketplace. SDGE, Edison, etc had to sell off all their power plants. The power providers than raised the prices skyhigh and limited supply artificially b/c they wanted to sell to the SECOND queue and get more per kilowatt and not the first queue where they get a lower price.
The governor forced a cap on rates to try to fix the problem (which of course did nothing). Multiply this market manipulation by power providers by the fact that a few power plants are offline and you get a bona fide "crisis" This governor knows the crisis is artificial and threatened to seize control of the power suppliers in the
state of the state address.. Thus this event was caused by deregulation, and the lack of power in the grid is not by accident.
The solution is now going to be California buying power in long-term contracts and reselling it to the power companies to sell to us. We shall see if it works.