Chicks from farm stores have already undergone shipping stress. Often the set ups to keep chicks in are less than ideal. Then they get further stressed by being transported home. Did you give chick saver or other vitamin in their water? Were they warm enough where you keep them? Diseases are less likely in chicks because they have not been around long enough to develop disease unless they were hatched with it. And then the chicks would keep on dying if they were all sick. Just a few points to help others you might buy. So sorry to hear you lost some.