The president's words absolutely matter, but what he does next will matter much more than what he said today.

Our thanks to Anderson Cooper, as always, I am Chris Cuomo and welcome to Primetime.

13 U.S. troops, mostly Marines, killed today in the worst loss of American life in 10 years in Afghanistan.

Remember them.

Imagine being their families.

If you know any of them, help them.

If any of them are watching right now, please know, we all owe you for what you and your loved ones gave for the rest of us.

And know this. You are not part of the problem that surrounds this situation.

You are the one aspect that all can agree on and appreciate as part of the solution, not the problem.

So think of our men and women who are still there, valiantly carrying on in a horrible situation.

Here is what the president of the United States said about this shameful tragedy.

These American servicemen who gave their lives, it's an overused word, but it's totally appropriate here where heroes.

The lives we lost today were lives given in the service of liberty, the service of security, the service of others.

To those who carried out this attack, as well as anyone who wishes America harm, know this, we will not forgive.

We will not forget.

We will hunt you down and make you pay.

We will not be deterred by terrorists. We will not let them stop our mission. We will continue the evacuation.

But how will it be changed to reduce the risk that this happens again?

Now, not since a chopper crash in 2011 have we seen death on this scale of our own.

13 dead, 18 others injured, some very badly. 60 Afghans may have been killed, more than 100 Afghans injured as well.

We don't know the real numbers because we don't control the area and know what happened today was not inevitable.

The chaos was not inevitable. This did not have to go this way and only this way.

...