My flock was fine yesterday. Today, when I went out to feed and gather eggs, about 2/3 were dead. This was 4 pens, including one pen 100 yds from the others, and a growing cage, with some chicks hatched last Easter, that had never had contact with the others. I threw 3 in a bag and set off for a state lab about 30 miles from here; by the time I got back, some that were healthy when I left were dead upon my return. I opened a fresh bag of feed yesterday, straight from the store; it looked fine. The chicks were on a different feed, though might possibly have had a couple of crumbles from the can I scoop with. The only birds not affected are some chicks, still in a brooder, that are indoors. I'm guessing everything outside will be dead by the end of the day. Any ideas? The first bunch.