if they r sent priority i think only usps ships them but for express mail i have had fedex be carriers along the routes and fedex likes to loose them and take longer cuz u can't track it when in their transits. usually if gotten there in 24 hours they r in better shape. if i remember right chicks have to ship at less than a day old or weigh at least 6oz. to be shipped if older. i thought it was against regulations to ship ones that little unless under 24 hours old. i'm betting they have AE from the hatchery, got chilled or a draft along the way or are week stock, i'd see how many u can save and let the hatchery know there is a problem and request replacements or a refund for the ones u have lost.
good luck!
good luck!