Dead chicken! Green skin, What do you think happened?

[Jmcintosh23]

She could’ve ate a bug that died from some posion. I checked the others and they have white/pinkish skin and they all seem healthy. Im not sure if the feed has vitamin k since the bag was thrown out. Next time we get them feed ill check the ingredients. We have been haveing trouble with algae in the water could that be have anything death related?

O algae in the water . Mine got out and could have drank from pond.. it's pretty green we have been trying hard to get it fixed right but so far still green and don't know what to do about that but could that be it...other chickens were nearby and still fine.