By Jonathan Kaminsky and Bryan Cohen DARRINGTON, Washington (Reuters) - Churches offered prayers on Sunday for dozens of people dead and missing from last week's mudslide in Washington state, as well as words of solace for grieving families, many still waiting for news of loved ones who vanished. The formal death toll rose to 21 on Sunday, including the remains of 15 victims identified by medical examiners and six still awaiting positive identification, said Jason Biermann, program manager for the Snohomish County Emergency Management Department. Source: Reuters