Sen. John Cornyn, R-Texas, said we must gather facts and determine how to prevent a similar tragedy.

CNN

Before making judgments about the shootings at Fort Hood, a thorough investigation needs to take place, Sen. John Cornyn of Texas said Thursday.

"It is imperative that we take the time to gather all the facts, as it would be irresponsible to be the source of rumors or inaccurate information regarding such a horrific event," Cornyn said in a statement.

"Once we have ascertained all the facts, working with our military leaders and law enforcement officials on the ground, we can determine what exactly happened at Fort Hood today and how to prevent something like this from ever happening again," he said.

Maj. Nidal Malik Hasan, an Army psychiatrist, shot and killed 11 soldiers and one civilian, officials said. Thirty-one people were wounded, officials at the Army base said. A federal official said Hasan is a U.S. citizen of Jordanian descent.

Cornyn, a Republican, said people should not jump to conclusions about what happened and why.

"We do not yet have these details," the statement said.

President Obama, who was speaking at a conference in Washington, said his administration "will make sure that we get answers to every single question about this horrible incident."

He asked Americans to keep the soldiers and families of Fort Hood in the thoughts and prayers.