presuming its there where u first destroy some of those skeletons with either green/red glow to them and the babe hanging in the center. once u killed all those off.
from where u entered this hangar: then u went on the ramp to the other side of the hanger to come down to floorlevel. that side where u came down from, standing in the middle, there should be a door u can open in the far right corner of the hangar.
*note : when u enter the door u can go straight outside or persue up the stairs to search the 2 buildings on top for some ammo goodies