NYTimes -- NASA Studies How to Make Remaining Shuttles Safe to Fly

Houston Chronicle -- Findings bolster wing theories

One focus of the board's inquiry is directed at the foam that is applied to the outside of the shuttle's towering fuel tank, the techniques for the application and changes that have been made in the application process throughout NASA's 22-year-old space shuttle program.

A series of analysis under way point to a forward section of the wing adjacent to the fuselage as the most likely site for a breach that could account for the damage discovered in the shuttle wreckage.

The suspected area of the breakthrough on the underside of the left wing closely approximates the region investigators believe was struck by a chunk of foam insulation from the fuel tank as Columbia lifted off on Jan. 16.