Paul Dwyer from Clinton, Iowa joined the Marine Corps in 1967, and eventually became a radio operator. 

"The very first day I walk into the communications building that they were having the training in and as I'm walking in the instructors up on this little stage were writing this big number 5 on the blackboard. He says, 'Welcome to field radio operator school.' He said, 'That number up on the board, that is your life expectancy in a fire fight in seconds.' And we all look at one another like, did he just say seconds? He says, 'Yes, I said five seconds. So listen up and you might learn some things that will keep you alive."

We have unidentified movement over here.

Dwyer went to Vietnam later that year. As days stretched to weeks and weeks to months, several truces were negotiated. But the North Vietnamese Army and Viet Cong seldom honored the agreements, and in January of 1968, Communist forces launched their largest offensive of the war. It began on the Vietnamese New Year known as Tet. And what came to be known as the Tet Offensive caught U.S. and South Vietnamese forces totally by surprise. 

Dwyer's unit was ordered to take back the ancient royal capital of Hue City. 

Initially, only light weapons could be used because commanders wanted to preserve the ancient Citadel. But the tight quarters and house-to-house fighting forced a grim decision over the fate of the city. A tall tower stood between Dwyer's unit and victory. 

"I can still remember it vividly. I had called in air strikes on the other side of it but they dropped napalm so there was fires on the back of this tower. And these NVA were running up over the top of the rubble pile from the tower and it looked like they were running up out of hell because the fire was in the back of them. It was very, whoa. We cut them down and then our guys went back up there and we didn't have any more problems with that."

The Marines eventually won the battle but the ancient city they fought so desperately to save lay in ruins.