President Barack Obama has ordered that flags be flown at half-staff today on memory of soldiers killed in a shooting rampage yesterday at Ft. Hood, Texas. 

The flags will remain at half-staff until Veterans Day.

Obama on Thursday called the shootings "tragic" and a "horrific outburst of violence." The president spoke at the Interior Department yesterday.

Maj. Nidal Malik Hasan, the suspected gunman, was shot after his attack that killed 13 and wounded 30, and is in critical condition.

Congress will also observe a moment of silence for the victims of the shooting this afternoon. Flags over some congressional office buildings are also at half-staff.

Sam Youngman contributed to this report