How does Alex die on mcleods daughters?

When he comes back from Argentina, Stevie is driving them back for a welcome back party. They stop to move some branches of the road. Stevie falls over, Alex helps her up they begin kissing, then suddenly the tree they are standing under falls, Stevie manages to move it time, but the tree falls on Alex. Stevie felt that morning that something wasen't right, she had a dream that she had a little baby, the pot on stove bubbling the baby screaming and Alex isn't there.