Losing a Friend.

Recently i have kinda felt like i've been loosing one of my friends. It makes me really sad. We used to be really close and now they just seem to be pulling away. I used to talk to this friend all the time. and tell them everything. but now we barley talk.and when try i get one word answers that i can't really do anything with. I really hope i didn't do anything to offend this person. or something. I really hope things will get better. But i don't know if they will. I really don't want to loose another friend. :(