  In this paper, we develop Leray-Serre-type spectral sequences to compute the
intersection homology of the regular neighborhood and deleted regular
neighborhood of the bottom stratum of a stratified PL-pseudomanifold. The E^2
terms of the spectral sequences are given by the homology of the bottom stratum
with a local coefficient system whose stalks consist of the intersection
homology modules of the link of this stratum (or the cone on this link). In the
course of this program, we establish the properties of stratified fibrations
over unfiltered base spaces and of their mapping cylinders. We also prove a
folk theorem concerning the stratum-preserving homotopy invariance of
intersection homology.
