Save the game if you want then use some level up points you may have stored (for imported characters). Continue forth until you encounter some husks. Shoot them all then continue forth.
Next, climb down the ladder and melee the husks. Continue inside the building for a scene. Once you're back in control, pick up some ammo on the floor then head out. Continue following the path until you encounter a couple of injured soldiers on the ground. Kill the Cannibals on the other side then talk to them again to open the path to the next area.
Continue forth and grab the medi-gel along the first corner. Kill the first group of Cannibals then move along. You should be able to see the gunship wreckage ahead. Go there and pick up the M8 Avenger assault rifle before activating the radio. More enemies will appear; dig in and kill them all until your cavalry arrives.