Nov. 2005 Marine Corps Gazette article posted on Military.com - Infantry Squad Tactics. Excerpt follows:

"Historically speaking, military operations on urbanized terrain (MOUT) have created casualty figures that are extraordinary compared to similar operations conducted in different types of environments. The casualties in MOUT present a significant challenge to small unit leaders. Casualties in Fallujah hit Marine infantry squads and fire teams extremely hard because, generally speaking, the squads were already under table of organization standards. Some squads in 3d Battalion, 5th Marines (3/5) commenced the assault on the Jolan with only six Marines. It is the small unit leaders' duty to accomplish the mission with the fewest casualties possible. In order for small unit leaders to complete the above task they need tactics and techniques that will prevent casualties..."