Washington (CNN) - President Barack Obama on Thursday called the Fort Hood, Texas, shootings "tragic" and "a horrific outburst of violence."
He expressed his condolences for the shooting victims.
"These are men and women who have made the selfless and courageous decision to risk and at times give their lives to protect the rest of us on a daily basis," he said.
"It's difficult enough when we lose these brave Americans in battles overseas. It is horrifying that they should come under fire at an Army base on American soil."
Government authorities are working to ensure that Fort Hood is secure, he said. The president asked for all Americans to keep the soldiers from the base "in their prayers."
There is no greater honor or responsibility as president than making sure U.S. soldiers are properly cared for, he added.
"We will make sure that we get answers to every single question about this horrible incident," he pledged.
Twelve people died in the shooting - including a gunman - and about 30 were wounded, a Fort Hood spokesman told CNN.
Updated: 5:36 p.m.
Related: Eleven killed, plus gunman, in Fort Hood shootings, officials say
Related: Fort Hood, a home to thousands
What a world we live in.
Unfortunately it's getting worse and worse by the day. With all we've learned from the past, all the education and technology we have and yet still barbarians in many ways.
My condolences to the families who have lost love ones. RIP.
I dont understand what is wrong with people sometimes.
So very sad. I am at work, trying to understand more and am curious what motivated somebody to do this to American troops? PTSD? Troops are people too and tak'in a beating already both at home and away – they don't need this... so sad
Keep the prayer with them and Give them comfortable like Jesus did
Such a sensless tragedy. My thoughts are with the family of those killed and the entire community in Ft. Hood. How did this kind of violence become an option in order to cope?
My father was once stationed at Ft. Hood, 1st Cavalry. May the victims and their families find peace.
The number of tours each man in the Service is doing may have something to do with this,lets hope not.This War has got to stop.Bring the troops in Iraq home now.
Prayers for families and fellow servicemen and women who have been affected by this terrible tragedy.
I send my condolances to those on Fort Hood.
Let's continue to remember that guns don't kill people, but rather it is people using guns that kill people.
To all my brothers and sisters at arms in Fort Hood!! Keep Your heads high at times like this.. We dont know what was in there minds to commit such a tragety!! Tomas Garcia is my cousin! he is based there but is currently in afganistan dont know if its more dangerouse there or in fort hood??
My thoughts and prayers are with those who lost their lives, the wounded, and te families and friends of all of them. This is shocking, I was just in Ft. Hood less than a month ago. It isn't good at all that soldiers should have to live in fear in their own home land. Hopefully they will get to the bottom of the situation quickly.
This is an absolute tragic. My thoughts and prayes are with families of our service men and women. God Bless America.
I'm here in Austin. I was at Ft Hood for 6 years. My heart and prayers go out to the victims and their families and to the military community at large. Despite what politicians do, you are all thanked everyday for your service. I feel your pain as a veteran. Stay strong and watch out for each other, in battle and in peace.
God Bless our military.
Very sad ..... very sad indeed
The greatest thing all you civilians can do right now is stop anyone in uniform and thank them for their service. If you see a vet, do the same. It makes a world of difference, trust me.
My condolences to my comrades in arms...I will pray for you all.
I live on Fort Hood and have for 6 years.. we will pull together and get through this as all military families do. This is a very sad tragedy. Our heart go out to the families.
My prayers go to my 1st cav brothers and sisters at Fort Hood, please lets stop this unneeded killings. God rest there souls.
I'm a veteran of the U.S Army; that being said, and ALL politics aside, this is a dark day for my brothers and sisters who wear the Nations uniform to defend our home and our way of life. My heart goes out to the Ft. Hood community, and I pray to God Almighty that they find comfort in this seneless tragedy.
I have lived on Fort Hood for 6 years and the support on the installation is above and beyond. We will pull this sad tragedy.
As a former Army soldier in the 80s, I am simply horrified by this shooting, BY AN ARMY OFFICER, of HIS OWN compatriots. Our base (I work on an Army base as a civilian member of the team now) is on increased security and glued to the news updates. We are all devasted. Our hearts go out to those who are injured, and those who have lost loved ones, as well as the entire Fort Hood community. A terrible day for the entire Army family!
this is horrific. I'm not an American, nor a soldier, but I empathise & sympathise with those survivirs & their families, and I'll pray for those who have died. Only God knows why, for sure!
What a sad tragic day in America my heart goes to all those affected families.
I have lived on Fort Hood for 6 years and the support on this installation is above and beyond. We will pull this sad tragedy.
During times of senseless tragedy we often ask ourselves why has God allowed this to happen? I tell you to remember this, if you believe in God you must also believe that there is another force at work in the world, Satan is his name. He feeds on those who are weak and vulnerable, not of the right mind, he finds his way into their hearts and creates distruction wherever he goes. This sad and terrible tradegy of senseless death and lives wasted with no purpose is such a case. Now is the time to ask God to give strength to the families and to those who have suffered injuries and loss. Do not waste your breath wishing ill on those who perpetuated this act, if they are not already in hell they soon will be. God bless America and God bless us all.