How old was Gandalf the great when he died. how did he die

2,019 years of age It is Gandalf's death that precedes the event where he turns into "Gandalf the White", although it is not exactly a metamophosis. In the Fellowship of the Ring chapter "The Bridge of Khazad-dum" Gandalf confronts a terror of the ancient world, a Balrog of Morgoth, in Moria