Officials say they are seeing progress in Afghanistan, but it has come at a cost for one Marine unit.
Ten families who saw their sons and husbands off from Camp Pendleton less than a month ago already have gotten word they will not return.
In the last week, the 3rd Battalion, 5th Marines has lost 10 Marines in Helmand province's Sangin district.
The oldest was 26, and the youngest, 19 years old.
It's where a third of all British military deaths have occurred. The British pulled out of the area only a few weeks ago, leaving the violent patch of land to newly arrived Marines.
Lance Corporal Alec Catherwood, 19, was shot to death on a foot patrol. Lance Cpl. Phillipe Vinnedge, also 19, died in a massive roadside bomb blast in the same vehicle as Victor Dew, 20, Joseph Rodewald, 21, and Justin Cain, 22.
Lance Cpl. Irvin Ceniceros, 21, was killed while on patrol, as was John Sparks, 23, James Boelk, 24, squad leader Ian Tawney, 25, and the oldest in the group, Joseph Lopez, 26.
Only one in the group, Tawney, had been in a war zone before, in Iraq. For the rest of these young men it was the very first time.
U.S. military leaders say they have Taliban fighters on the run, forced out of some areas they have controlled for so long.
Marine Unit Suffers Sobering Week as U.S. Troops Continue Push into Kandahar
The goal in the south is to isolate Kandahar city from Taliban fighters, cutting off ammunition supply routes in and out of the city and then hammering hideouts and bomb factories that surround it.
Back in August, surge forces began moving up from the southern borders of Kandahar city. The U.S. troops then attacked Taliban command posts in the north and the southwest.
This weekend, they began an assault from the west.
ABC News' Richard Coolidge contributed to this report.