JOHN ROGERSLOS ANGELES (AP) â¿¿ Southern California Edison is reaching out to hundreds of thousands of customers who were left without electricity â¿¿ some for as long as a week â¿¿ during a devastating windstorm last month. Edison will do better next time when it comes to restoring power and keeping people informed about the efforts, president Ron Litzinger wrote in a letter of apology to customers, noting the company has learned from its experience. "While our repair crews performed extraordinarily well, we will learn from the comments received from our customers during the past week to improve our response to similar events in the future," Litzinger wrote in the letters that began going out in the mail Friday. The state Public Utilities Commission has launched an investigation into Edison's response to the storm. Southern California Edison is a division of Edison International. The letters were being mailed to all of the 430,000 Edison customers who lost power during the Nov. 30 storm that spawned wind gusts approaching 100 mph in some areas. An additional 213,000 homes and businesses served by other utilities also lost electricity. "We would like to apologize for your inconvenience and thank you for your patience and understanding during this significant event," Litzinger wrote. The crisis caused by the storm was unprecedented in Edison's history, company spokeswoman Vanessa McGrady said. Hundreds of downed trees tangled dangerous high-voltage power lines and blocked streets, keeping repair trucks from reaching many hard-hit areas. Numerous uprooted trees remain on sidewalks and in gutters in some areas. "A crisis of this magnitude we had never had before," she said. Several San Gabriel Valley cities east of Los Angeles, including Pasadena, San Marino and Arcadia, suffered extensive damage. Three-quarters of the homes in Temple City, 15 miles east of Los Angeles, were without power at one point. Some didn't have it restored for a week.