No pool cover? is the temp suddenly quickly thawing ice and snow? Do you think it has a leak? just a guess but with out cover, maybe a leak with sudden thaw, water level dropped, ice stuck to side walls and pulled on liner as it sank? I am not sure on the saving part without actually seing it. Hopefully someone can help who has had an issue with something similar. I am curious on why. Just a quick opinion looking , looks like it might be stretched out and tough to get back in place