Please help. ASAP

My chicken had passed away yesterday. She was completely fine and normal the entire day until when it fell night we found her at the bottom of the coop laying with her head down. We brought her in and she was still alive but was very weak and kept twitching. We tried to feed and give her water but she did not eat or drink. I went to sleep beside with a heat lamp and the next morning she died. She wasn’t injured or hurt and she was literally normal in so in shock that this happened all in the span of a couple hours. I’m not sure how she died, before she did she had thrown up blood as when I picked her up to bury her there was a small pool of it near her mouth. She usually was the one who escaped the backyard so me and my family suspect she perhaps ate something.

Is it possible she ate something or do any of you know how she could have died? We are taking the other chickens to the vet but I just kinda want answers now.