WASHINGTON — President Barack Obama today said the "whole nation is grieving right now" over the mass killings at Fort Hood. He urged people not to jump to conclusions while law enforcement officials gather facts about the shootings.

The president today ordered flags at the White House and other federal agencies to be flown at half-staff until Veterans Day as a tribute to those who lost their lives.

A shooter went on a rampage that left 13 people dead and injured 30 others at the sprawling Army post in Texas. Obama promised to update the nation as his administration learns more about what happened.

The suspected shooter, Maj. Nidal Malik Hasan, was shot and remains hospitalized. The motive for the incident is unclear.