A natural gas well blowout last year that crippled a major energy supply for Southern California could lead to blackouts in the region over as many as 14 days this summer, energy officials said Tuesday. State agencies that studied the impact of the partial shutdown of the Aliso Canyon gas storage field proposed an action plan to prevent power outages but concluded they "will reduce, but not eliminate, the risk of gas shortages this summer that are large enough to cause electricity interruptions for the region's residents and businesses."