PHILADELPHIA: AC/DC is losing another member. Bassist Cliff Williams has announced his departure from the group in a video posted on the band's YouTube channel Tuesday, the same day the group wrapped up its 'Rock or Bust' tour in Philadelphia. Williams says he's 'just ready to get off the road' and needs more time for family and to 'chill out.' Williams is the second AC/DC member to depart the band this year and the fourth since 2014. Lead singer Brian Johnson stopped touring in March amid concern about hearing loss. Guitarist Malcolm Young retired due to health reasons in 2014 and drummer Phil Rudd left the band that same year amid drug charges. Williams says the departures didn't play a part in his decision to leave the group.