SAN ANTONIO -- In response to the rampage at Fort Hood, a spike in blood donations has been reported at Brooke Army Medical Center and Wilford Hall Medical Center.

"We took almost half of our blood supply from here and sent it up to Fort Hood," said Lt. Col. Clayton Simon, a medical officer at the Akeroyd Blood Donor Center at BAMC. "We were expecting to get some of the casualties here."

Among those who felt compelled to donate blood after Thursday's violent attack was Staff Sgt. Cody Nixon.

"It's important all the time to give blood because they need it, so I decided to come," said Nixon, who has one of the needed blood types.

Blood donations will also be needed after the immediate aftermath because blood is only good for 48 days, so maintaining a robust supply is vital, said Simon, who is urging other military and the public to keep giving blood in the days and weeks ahead.

"That's the way it should be done," Simon said. "It's best to get a full supply today and sustained over the next couple of weeks so that we're not at the same low level come Christmas."

In addition to sharing its blood supply for the medical response at Fort Hood, BAMC also dispatched a team of 15 psychiatrists, psychologists and mental health professionals.