A Fort Hood soldier from Tyngsboro said yesterday he’s stunned the man suspected of turning the Texas base into a killing zone, murdering 13 and wounding 28, is a psychiatrist entrusted to help GIs.

“The biggest shock was finding out his rank and what he did for the Army,” said Sgt. Timothy Dunbar, 28, who works for command staff at the base. “I was just completely lost for words.”

Dunbar, a 1999 Tyngsboro High School graduate, said he had just left a USO event in Dallas with Brig. Gen. William Grimsley when the second-in-command at Fort Hood was delivered the news about the shooting rampage.

Army psychiatrist Maj. Nidal Malik Hasan reportedly yelled “Allahu Akbar” - Arabic for “God is great” - as he allegedly opened fire Thursday.

“I didn’t know 100 percent of everything that was going on,” said Dunbar, who drove Grimsley and his wife 170 miles back to the base. “The numbers kept growing as we were coming back. We had to get him on post. It was treated like a terrorist attack.”

Dunbar said vehicles were backed up on roads approaching the base because no one was permitted to enter or leave Fort Hood. Dunbar said he was given permission to pass because Grimsley was in the vehicle.

“There was nothing but cars backed up for miles,” said Dunbar, who described the scene as “eerie.”

Dunbar lives on the base with his wife, Christine, and four children, ages 2, 3, 5 and 8, who are all safe.

Lynn Murray of Sudbury said she was relieved because her son, Brad, 21, was about 12 miles away from the post for a multiday training yesterday.

Brad Murray is an Army private first class assigned to the 3d Armored Cavalry Regiment. He lives there with his wife, Crystal, who is a nursing student.

“My heart just weeps for the other moms who won’t be able to hear their loved ones’ voices,” Lynn Murray said.

In Wayland, Eleanor Lagasse said her grandson, Robert, 29, a civilian groundskeeper on the base, is OK.

“I really was a little afraid when it first happened because I didn’t know whether (he) was on the base. But he wasn’t,” she said. “I was happy for that.”