BAGHDAD, IRAQ - JULY 13: Spc. Derek Vobornik (L) and Sgt. Angel Martinez of the 1st Battalion, 5th Cavalry Regiment of the U.S. Army attempt to get a computer system working in a Saddam-era bunker that's being converted to an Army field post.

BAGHDAD, IRAQ - JULY 13: Spc. Pipier Solano of Chelsea, Mass. (L) and Pfc. Daniel Sims of Clemson, South Carolina of the 1st Battalion, 5th Cavalry Regiment of the U.S. Army sit during watch duties in a partially destroyed building.

BAGHDAD, IRAQ - JULY 13: An US Army officer passes outside a Saddam-era concrete bunker that's being converted to an Army field post in the tense Amariyah neighborhood of Baghdad, Iraq.

BAGHDAD, IRAQ - JULY 13: A soldier in the 1st Battalion, 5th Cavalry Regiment of the US Army sleeps on a cot in a crude hallway in a Saddam-era fortified concrete bunker that's being converted to an Army field post.

BAGHDAD, IRAQ - JULY 13: An original sign in English and Arabic of a Saddam-era fortified concrete bunker that's being converted to an Army field post in the tense Amariyah neighborhood of Baghdad, Iraq.

BAGHDAD, IRAQ - JULY 13: US Army soldiers of the 1st Battalion, 5th Cavalry Regiment inspect the basement of a Saddam-era concrete bunker that's being converted to an Army field post in the tense Amariyah neighborhood of Baghdad, Iraq.

BAGHDAD, IRAQ - JULY 13: U.S. Army soldiers of the 1st Battalion, 5th Cavalry Regiment walk across the main floor of a Saddam-era fortified concrete bunker that's being converted to an Army field post in the tense Amariyah neighborhood of Baghdad, Iraq.

BAGHDAD, IRAQ - JULY 13: A soldier of the 1st Battalion, 5th Cavalry Regiment walks through a vault-like door of a Saddam-era fortified concrete bunker that's being converted to an Army field post July 13, 2007 in the tense Amariyah neighborhood of Baghda

BAGHDAD, IRAQ - JULY 13: Soldiers in the 1st Battalion, 5th Cavalry Regiment of the US Army unload a Bradley personel carrier at the entrance of a fortified concrete bunker that's being converted to an Army field post is seen July 13, 2007 in the tense Am