11.   They arrive from the surrounding slums, where people live under corrugated steel roofs and wash in gutter water.

12.   This is a series of concrete pads with retractable corrugated steel roofs that can be left open to the sun and closed when it rains.

13.   But many here still live in prefab temporary housing, and some shops are still located in corrugated steel buildings.

14.   It involves attaching concrete slabs to corrugated steel sheets, but experts said ceilings built with the method would last only a few years.

15.   The workers swung their crowbars with a clang into the corrugated steel and pried it loose.

16.   Workers cleaning, painting and remodeling the center have given a building that already looks industrial a new layer of corrugated steel and scaffolding.