Have had my chickens about 4 1/2 months, They're about 7 months old now. Been laying for about a month. Got home from work this morning & chickens were running around doing chicken stuff. Gave them a couple tomatos. Went out an hour later & a RIR hen was laying on the ground barely moving. Died about 5 minutes later. She was the roosters favorite so I don't know if they could of broke her back/neck or what. I started out with 6 birds, 2 that turned out to be roosters. They were taking turns with her when I found her. Any other ideas as to what could of happened or caused it or a disease I should be aware of? Their coop is elevated & they do tend to fly out the door sometimes. They only free range occasionally & are supervised when out, Haven't let them out in about a week as I have been on OT at work & didn't have time to spend watching them but they are out daily in an enclosed run.