Green caterpillar with yellow hairs and black ends. Wasn't there an hour ago and looks like it stopped building the cocoon halfway. (Central Colorado)

I was reorganizing the garage and left for a bit. When I came back this empty spot suddenly had a half built cacoon and the caterpillar aimlessly wandering near it. I thought building a cacoon took a lot of energy, so it's odd that it stopped. Is there anyways I could help it, or is it DOA?