A substantially flat disposable absorbent article for wearing adjacent a body discharge area having a longitudinal centerline, and a lateral centerline orthogonal thereto, and defining longitudinal and lateral directions respectively. The disposable absorbent article includes a liquid pervious top sheet, a back sheet joined to the top sheet, and an absorbent core intermediate the back sheet and the top sheet. The absorbent core includes a layer of compressed, cellulose based, linear fibers for expanding the article into a tridimensional structure while being worn by a user. The layer of compressed, cellulose based, linear fibers is activated by body fluids.