Katie Couric's Notebook: Fort Hood

A 21-year-old soldier joined the Army to see the world. It's the beginning of too many tragic stories we've heard since October of 2001.

But Michael Pearson wasn't killed in Afghanistan or Iraq. He died at Fort Hood when Nidal Malik Hasan opened fire yesterday afternoon.

The 13 people killed and the 30 wounded are only the beginning of the ultimate toll. The Readiness Center is meant to be a safe place where soldiers can prepare to deploy and where they can heal and begin to forget the nightmares. Now, it has become another horrific memory for survivors.

At least 300-thousand soldiers who have fought in the wars since 9-11 are suffering from post traumatic stress disorder.

We don't know yet what motivated Hasan's murderous rampage. We only know there are many young men and women who served bravely but are suffering greatly.

It is the nation's responsibility to give them the care they need and the security they deserve.

That's a page from my notebook.

I'm Katie Couric, CBS News.