U.S. death toll in Afghanistan hits 2,000, but many more lives turned upside-down

(CBS News) FAIRFAX, Va. - The war in Afghanistan has just passed two milestones this week: It has lasted more than 3,900 days and it has cost 2,000 American lives. But there is one statistic we can't give you - the number of lives changed by each of those deaths. There are too many to count.

The number 2,000 only begins to tell the story of what's been lost in Afghanistan.

Take 21-year-old Nicholas Kirven, gunned down by insurgents on Mother's Day 2005. It was his last mission before he was due to come home.

His mother Beth signed the papers for him to enlist in the Marines right after 9/11. He was 17.

"He had to get my permission," says Beth. "I had to sign the form."

Widow of first servicemember to die in Afghanistan War still struggling with loss

Then there's his stepfather Michael, his younger brother Joseph, and older sister Pride.

"She lost her best friend," says Beth. "Joseph lost his big brother."

That makes four people whose lives will never be the same. "It changes who you were. It changes where your children fit. It really changes who you are," Beth says.

Watch Pride and Joseph Kirven talk about their brother Nicholas, whose was killed in combat in 2005:

Then there's Lexi Bastian, whom Nick fell in love with while stationed in Hawaii. "It's hard for her," Beth tells CBS News.

The story of what was lost is all around the house where Nick grew up. His ball cap and scarf came back with his personal effects, the first thing the family took out of the box from Afghanistan.

Beth wouldn't clean the hat off. "Came back just the way he wore it and that's how I wanted it to stay," she explains.

There are pictures of Nicholas all over the house. But one is special. It shows Nick in a bar. His head is partially obscuring a neon sign in the background. Beth says it answered a question she kept asking.

"'Are you really in a better place?' 'Are you really happy?' And for the first time, I saw lettering to the side of his head and I focused in to see what it says and you can see what it says," Beth says. The neon words: "It's great."

There's a debate in the family about whether there are too many reminders of Nick, making their house more shrine than home. His combat boots, which are more heart wrenching then his mother realized until this very moment.

The boots, Michael says, are the ones Nicholas died in.

"I didn't know that," says Beth turning to him, sobbing for a moment.

And then there's a hat that Nick died in, says Michael, brought to them by a sergeant who was there.

"The sergeant really had a hard time with all this," Michael says, "and sort of went off the deep end and - post-traumatic stress."

More than 2,000 dead. They are the ones who sacrificed the most. But behind them are thousands more still reeling.