US forces continue advance through Iraqi capital

OUTSKIRTS OF BAGHDAD, Iraq -- The road led to what looked like a carport -- a really long one, but a carport nonetheless. At the rear, though, was something far more interesting to U.S. forces.\nA door. And behind it, lined with moss, a cave entrance -- another mysterious, potentially dangerous gateway into the murky world of Baghdad Underground.\nWas this a path to one of Iraqi President Saddam Hussein's notorious hideouts? Were booby traps -- or, worse, Iraqi soldiers lurking inside?\n"We wanted to know if there was enemy in there. We thought there was enemy in there," said Lt. Col. Lee Fetterman, commander of the 101st Airborne's 3rd Battalion, 3rd Brigade.\nYears of rumors about tunnels Saddam had built raised the possibility that just about anything could be underground -- troops, weapons of mass destruction, the Iraqi leader himself.\nA former Iraqi scientist who fled during the 1991 Gulf War, Hussein al-Shahristani, told CBS' "60 Minutes" in February that there were "more than 100 kilometers (over 60 miles) of very complex network, multilayer tunnels."\nBut he never saw them himself. Few have, said Patrick Garrett, a military analyst at Globalsecurity.org. \n"There is tons of conjecture on this subject right now," he said, but "there's been no official confirmation or official imagery."\nSo far, a series of tunnels under Baghdad's international airport have been discovered. On Monday, U.S. forces captured an Iraqi colonel in one tunnel who was calling in artillery fire from his hideout, said Lt. Mark Kitchens, a spokesman for the U.S. Central Command.\n"Obviously for the type of regime we're dealing with, the tunnels represent an ideal spot to conceal weapons and serve as a hideout and in some cases an escape route," he said.\nThe area near the airport had already seen days of skirmishes when forces from the 101st Airborne Division secured it fully on Tuesday.\nThe troops at the airport belong to a unit known as the "Iron Rakkasans" because of strips of burlap connected to their helmets -- "iron hairs" -- that distinguish them from other fighters in the division.\nThe Rakkasan nickname dates to World War II, when the 187th Regiment, 3rd Brigade, parachuted from planes. Loosely translated in Japanese, "Rakkasan" means falling down umbrellas.\nThey were brought to Baghdad because they are light infantry fighters, highly trained in urban combat. Their particular skill is room-clearing, which they used searching for al Qaeda fighters in caves in Afghanistan.\nTo reach the carport, they crossed a landscape of bombed compounds, piles of unexploded ordnance and a field of dead Iraqi fighters, their bodies blackened from coalition attacks.\nWhen the American forces got to the carport, they initially believed it to be one of the intricate tunnel systems that dots the Iraqi capital. That was nerve-racking in itself: Over the weekend, during the night, two Iraqi fighters had popped up from a tunnel on the airport grounds and were chased by U.S. forces into the darkness.\nCarefully, about 150 U.S. soldiers headed out to explore it, first donning the night-vision goggles.\nThey went past the nearby lake, past the lakehouse. They went into the cave mouth, through shin-deep mud and down a set of dark stairs. Then they went in the door.\nInside, they found 12 rooms, each with white marble tile floors, 10-foot ceilings and fluorescent lighting.