More is being learned about the victims of Saturday's helicopter crash in the Grand Canyon. Authorities say Becky Dobson and her boyfriend Stuart Hill were killed in the crash. They attended the autumn wedding of fellow passengers Ellie Milward and Jonathan Udall. Milward and Udall are among the crash's four survivors. They are in critical condition at University Medical Center in Las Vegas. Stuart's older brother Jason Hill was also killed in the crash. All the passengers were from the U.K.