Date of birth: 22 January 1950
Date tour began: 12 October 1968
Date of casualty: 25 May 1969
Home of record: Oregon City, Oregon
Branch and Rank: Marine Corps, Private First Class, Machine Gunner
Unit: 1st Marine Division, 2nd Battalion, 26th Marines, F Company
Awards: National Defense Service Medal, Vietnam Campaign Medal, Vietnam Service Medal
Location of name on the Vietnam Wall: 24W, 107
 
Location of service: South Vietnam, Quang Nam province
Died through non-hostile action .. accident
 
Schools Attended: Oregon City High School
Burial location: Willamette National Cemetery, Portland, Oregon
Memorials: Vietnam Veterans Memorial (Washington, DC), Oregon Vietnam Veterans Memorial (Portland), Veterans Memorial Coliseum (Portland), Oregon City High School Memorial Garden
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The Oregonian, Thursday, May 29, 1969
Blast Kills U.S. Marine
OREGON CITY (Special) – Marine Terry A. Sundeen, son of Mr. and Mrs. Ernest Sundeen, 1600 Division St., Oregon City, was killed Sunday near Da Nang, South Vietnam, when a grenade exploded in a trash fire he was tending, his parents were informed.
Pfc. Sundeen had been in Vietnam since last September. He joined the Marines in March, 1968. He was born Jan. 22, 1950, in Mayville, N.D., and moved to Oregon City in 1956 with his parents, where he received his educations.
Besides his parents, he is survived by three brothers and four sisters. Funeral arrangements are pending.

 
The Oregonian, June 4, 1969
SUNDEEN – Terry A., Pfc. US Marine Corps, in Vietnam, May 25th; beloved son of Mr. and Mrs. Ernest Sundeen, Oregon City; brother of Lorin, Ernest, Steven, Mrs. Don (Patty) Lane, Mrs. Harley (Emily) White, Mrs. Arthur (Alice) Moore, Mrs. Keith (Connie) Barringer. Friends invited to graveside services at Willamette National Cemetery, Thursday, June 5, 3 pm. Remains will lie in state at the HILLSIDE CHAPEL, Oregon City, until noon Thursday. Friends who wish may call at the funeral home.