Found one of my hens dead

[Sissymomoften]

Found one of my Orpingtons dead in coop. She is 1 of 5 Orpington but 1 of 21 chicks including Ameraucanas, Black Asians, Rhode Island Reds aging from 24-28 weeks. All seem to get along never have seem them fight or be ugly. We have raised them since a few days old. This is our first loss. What should I look for in the dead Orpington to make sure my other chickens are ok. Looked her over and she seems fat and healthy, no bugs that I can see, no missing feathers. Just other info not sure if it matters but had a bad lighting storm last night lasted a few hours and when I looked in her mouth there was a lot of food in mouth and throat.

 

[BullChick]

One possibility is an impacted crop. You said “chick.” Was she young enough to have pasty butt? If left untreated, it can kill.
Regardless of what happened (I am sorry by the way!), it doesn’t sound like something the others will succumb to.