Sick baby chickens

[endergirl]

i had 4 little chickens.
but one of them had whitish tips on his wings.
then they spread to all others and the smallest one died.

Then the other chick got a bit dizzy and lazy always sitting. i tried to chase it a bit, it ran.
but i noticed that the white wing tips spread to the whole wings

i was looking in the internet but cant find the disease or how to treat it.