CBS has announced that after 72 years and more than 15,700 episodes, Guiding Light, the longest-running soap opera on TV, will air its last show on Sept. 18. A press release issued by the network doesn’t give an explanation for the cancellation, but many believe that the show’s low ratings (hovering at 2.17 million) are to blame. The release also doesn’t specify what program might take the place of Guiding Light, which started as a radio serial in 1937, but a talk-show would be a logical replacement. “Guiding Light has achieved a piece of television history that will never be matched; it has crossed mediums, adapted its stories to decades of social change and woven its way through generations of audiences like no other,” CBS Entertainment president Nancy Tellem said. “This daytime icon will always be an indelible part of CBS’s history…. Its contributions will always be celebrated and never be forgotten.”