I had chickens, geese and ducks as a child but this is my first time having chickens as an adult. Two weeks ago we got 6 pullets - Barred Rock, White Rock, Speckled Sussex , Buff Orpington, Black Star and Red Star. All 6 weeks old except the Speckled Sussex who was just 2 weeks. We got them at the chicken swap. The Sussex died a week ago and then the Red Star. The White Rock died today. All were eating and drinking and playing with the others when they started sneezing and then they began to slow down. Orange watery poop, then they died. They're in a coop with a heat lamp. Sawdust/wood chips on the floor and they're eating Start and Grow. Any thoughts or ideas are desired. A couple days after we got the first batch we got 3 more. One is a 12 week old Maran and the other 2 are 4 week old Easter Eggers. Those we got from a breeder. I should have waited and made sure the swap pullets were healthy before adding more, I see that now. I 'm concerned about the rest of my flock. Antibiotics? Different food? I'm willing to try most anything. Thank you!