Graham Nash on loss of David Bowie, Glenn Frey

There's been an outpouring of grief from the music world since the New Year as multiple legends have left us, including Natalie Cole, Lemmy of Motorhead Fame, David Bowie, and The Eagles' Glenn Frey, who died just a week later. Their music may be timeless, but age is catching up to a whole generation of classic rockers. Rock and Roll Hall of Famer Graham Nash spoke to "CBS This Morning: Saturday" co-host Anthony Mason about the loss of two contemporaries and his thoughts on his own mortality.