New York City Opera, created 70 years ago as the “people’s opera” because of its affordable tickets, filed for bankruptcy after years of declining income and a failed fundraising effort, Bloomberg News reported yesterday. The nonprofit organization, which this year produced “Anna Nicole,” about the late tabloid celebrity, listed as much as $10 million in assets and debt in a chapter 11 petition filed in bankruptcy court yesterday. The filing became necessary after the opera company fell short of an emergency fundraising goal of $7 million. The opera listed New York City Ballet as one of its biggest unsecured creditors, with a claim of $1.6 million, according to the petition.