Arizona's oldest continuously published daily newspaper put out its final print edition Saturday with a fitting last headline: "Our Epitaph." Saturday's 48-page commemorative edition of the Tucson Citizen was filled with individual columns by editors and staffers and highlights of the Citizen's 138 years of publication. The Citizen will continue as an on-line-only opinion Web site. The Tucson Citizen was one of two US papers that announced plans last week to publish their final print editions, but continue operating on-line, part of a growing trend that has shaken the news industry. The Ann Arbor News in Michigan plans to publish its last newspaper on July 23. Many newspapers across the country are struggling to survive mounting losses as readers have migrated to the Internet, advertising revenue has declined drastically and circulation has fallen. The Arizona Attorney General's Office didn't want to let the Tucson newspaper die without a fight. It filed a complaint Friday in federal court seeking to halt the closure. The complaint said that Gannett and Lee Enterprises Inc., publisher of the morning Arizona Daily Star, were closing the Citizen to increase profits to both companies, and doing so would "substantially lessen competition." Kate Marymont, Gannett Co. vice president for news, said late Friday company lawyers were studying the documents filed by Goddard but declined further comment. Marymont earlier Friday told the Tucson newspaper's staff that the paper would continue with a Web site edition providing commentary and opinion but no news coverage. Bob Dickey, president of Gannett's US Community Publishing Division, said in a statement that a Tucson Citizen editorial weekly will be printed in the morning Arizona Daily Star to expand the reach of the Citizen's voice. "Dramatic changes in our industry combined with the difficult economy - particularly in this region - means it is no longer viable to produce two daily printed newspapers in Tucson," Dickey said. In January, Gannett, the largest newspaper publisher in the country, announced plans to close the Citizen if it didn't find a buyer for certain assets by March 21. Only four days before the original planned closing, however, Gannett announced that the shutdown would be delayed because negotiations were continuing with two interested buyers. Those talks ultimately proved unsuccessful. It was unclear how many of the Citizen's 65 employees would lose their jobs. The Citizen has struggled for years against the Star, a 117,000-circulation newspaper. During the Citizen's heyday in the 1960s, circulation was about 60,000, but it had fallen to 17,000. The Ann Arbor News plans to continue after July 23 with a twice-weekly on-line-focused operation taking the place of the print edition. Publisher Laurel Champion announced the date Thursday in an e-mail to employees. The News reported in March it would cease publication after 174 years because of steep revenue losses. A Web-based media company called AnnArbor.com will emerge. Although the new venture comes from the same owner, the Newhouse family's Advance Publications, officials have stressed that AnnArbor.com will be built from the ground up, with the new free Web site being more than the old newspaper delivered in a new format. The new site will also produce a print edition on Thursdays and Sundays. The newspaper closure will eliminate 214 jobs. Seventy workers previously accepted buyout offers. AnnArbor.com officials have said they probably will hire some current staffers but have not said how many. Earlier this month, Democratic Sen. John Kerry noted at a special Senate hearing that layoffs, closings and cutbacks have turned US newspapers into an "endangered species." The Boston Globe in Kerry's home state of Massachusetts is facing the threat of closure unless it can cut costs. Members of the newspaper's largest union, the Boston Newspaper Guild, will vote on June 8 whether to ratify wage and benefit cuts that the newspaper's parent company, The New York Times Co., is demanding to keep the 137-year-old daily from closing. Already this year, E.W. Scripps Co. closed the Rocky Mountain News in Denver, and Hearst Corp. stopped printing the Seattle Post-Intelligencer, making it on-line only. The Christian Science Monitor stopped daily publication in favor of a weekly print edition with on-line news. Other major newspaper companies, including the owner of the Chicago Tribune and Los Angeles Times, have filed for bankruptcy protection.