NASA INVESTIGATOR MEASURES A 16-INCH HOLE DURING A TEST, 2003-07-07 (photo)

NASA investigator Dan Bell measures a 16-inch hole in a carbon-reinforced wing panel removed from shuttle Atlantis after a 1.67-pound piece of fuel-tank foam insulation was shot out of a 35-foot nitrogen-pressurized gun and slammed into it during a test in San Antonio, July 7, 2003. Engineers Monday found what they called the "smoking gun" in the destruction of the Columbia space shuttle, a piece of foam that struck the shuttle's left wing when it lifted off in January. Scott Hubbard, a member of the Columbia Accident Investigation Board, said a test carried out at the Southwest Research Institute in San Antonio "demonstrates that this is in fact the most probable cause creating the breach that led to the loss of Columbia. REUTERS/Eric Gay/POOL CMPELG/HB