Since the beginning of the war in March 2003, IEDs have accounted for about 45 percent of all U.S. fatalities from hostile causes. That percentage is increasing. Of 100 recent hostile fatalities, IEDs caused 67.

"U.S. meets foe it can't defeat" , By Brad Knickerbocker.   Christian Science Monitor January 01, 2007

The Days and Nights in Iraq - Chapter 1
The Ultimate Price ... - Chapter 3