Poor little chick. Sometimes the ones underneath the rest do get squished and don't survive, although they sure put up a fight. We lost two that way already this chick season. Keep her warm and be sure to eyedrop or syringe water with either sugar or Polyvisol into her, and check her strength. She might start out wobbly (like she's drunk), then not be able to walk at all, then not eat at all. If she's able to stand or doing better, keep her in a properly heated brooder with easy access to water to see if she can drink on her own. Offer Gro Gel if you have it; if you don't, grind up some chick starter and offer it as a powder or with warm water as a mash. Keep us posted, and good luck!