Happens sometimes. I've gotten shipments of hundreds of birds that were obviously left in post office transport vehicles for way too long that were pretty much all dead on two separate occasions. This was from a reputable hatchery that I have used for over a decade - and I continue to use them because 98% of their shipments come with 0 deaths. They know it's a risk to ship birds and the post office these days is slow as hell so it's even worse than it was pre-pandemic. This is just the cost of shipping birds unfortunately. I have ALWAYS ordered any chicks i need for the year in Feb or March for this reason. If you order at the last minute, you will get the least healthy birds of that hatch every time. Just the way they do things at most hatcheries. Early orders get the best birds. And of course it's better to get birds from the closest hatchery to you possible if you can.