In July 1977 , his son Karac died at the age of five while Plant was engaged on Led Zeppelin 's concert tour of the United States . It was a devastating loss for the family . Plant retreated to his home in the Midlands and for months afterwards he questioned his future . Karac 's death later inspired him to write several songs in tribute : " All My Love " featured on Led Zeppelin 's final studio album , 1979 's '' In Through the Out Door '' , while " Blue Train " featured on Page and Plant 's second and final ( studio ) album , 1998 's '' Walking into Clarksdale '' . The song " I Believe " on Plant 's solo album '' Fate of Nations '' is another tribute to his late son
concert tour of the United States
Led Zeppelin North American Tour 1977
Robert Plant