The war ended on April 30, 1975, with the fall of Saigon -- now Ho Chi Minh City -- to the Communist north, two years after the withdrawal of U.S. ground troops.
We have two very different accounts of that same extraordinary day. The first, from a U.S. veteran who helped execute a mass evacuation on April 29. The Air America pilot was a part of the largest helicopter airlift in history.
The second, from a retired Sergeant Major who was among the ranks of the North Vietnamese forces. He raised the flag on Davis Camp at Tan Son Nhut Airfield at 9:30 a.m. on April 30.
Air America helicopter pilot Robert Caron: We were in denial for a long time. We just didn't think it was going to happen because it had been going on for so long. We thought we'd be there another 10 years doing that. Then, all a sudden, bang, Da Nang fell and that was it.
President Thieu, although he had just got back from the U.S. and visiting Congress, telling them he was militarily and politically in control, we knew that was garbage, because he wasn't. In the middle of April, he jumps on a C-130 out of Vietnam. It indicated to everybody that this really was going to end soon.
The last two days, the Ambassador finally realized the end was coming, and he let people try to leave. But by then, the runway had mortar holes so you couldn't take off safely.
So it put the evacuation entirely on choppers.
Sergeant Major Nguyen Van Can: We had been staying in Davis Camp for days, I did not see very much out there.
It was only on the morning of April 30, when I climbed up to raise the flag, that I saw numerous Republic of Vietnam soldiers rushing the streets.
We were banned from listening to the radio. Our Captain wanted to keep us from the "Open Arm" program of the Republic of Vietnam.
What do you remember about the fall of Saigon?
Caron: They finally made the call to evacuate at 11 o'clock. With the clothes on our back, we ran out to Tan Son Nhut Airfield, trying to find a free helicopter to fly.
I found a chopper, jumped in, and started going out to the rooftops. When I went to the embassy, that's when CIA officer Oren "O.B." Harnage jumped up and said, "I got something I need you to do."
He told me we were to pick up the Deputy Prime Minister and his family. We took off, he directed me to where that rooftop was. As we approached, I said that the Deputy Prime Minister sure had a huge family, because there were 50 people standing on that ladder.
We kept ferrying people back to Tan Son Nhut Airbase, so they could get on the bigger helicopters and get out to the ships at sea. I had seatbelts for seven or eight people. We ended up carrying up to 20 people per ride.
Can: There are two moments that will stay in my mind forever. The first is the visit of President Duong Van Minh to Davis Camp on the afternoon of April 29. They requested a meeting with us. I am the one who opened the gate.
They came in three cars. Field guns were firing intensely. They were lying on the floor of the car, extremely fearful for their lives. They wondered why we were so calm. I told them, "We got used to this," and I laughed.
The second is the moment I climbed the water tank to raise the flag at Davis Camp at 9:30, April 30, 1975. It was a signal for our Army Force. It was a dead point up there. We could have gotten shot at any time.
What was the feeling on the ground when the fighting ended?
Caron: A lot of anger. How many people were left behind. There were thousands of people.
It was mass confusion. Bitterness that our government had lied. There was nothing we could do. We were like peons. We had no power. We flew around, did what we could. Got a few hundred people out, when we could've got thousands.
Can: When I raised the flag, I was fully aware that, "this is the moment." We were so happy. There was no more risk of getting killed. I felt such a strong desire for peace. After such a long period of war, it was like an explosion of feelings. We hugged each other and cried.
When the war was over, what do you remember doing, seeing, hearing?
Caron: Two words. Utter chaos. They knew their life was going to be miserable from then on out. The streets were blocked off. In the last day or two, there was martial law, so I didn't dare go out on streets, because I could have been shot. People tried to get into the embassy; to get onto any aircraft. It was just mass, mass panic by everybody, because they knew the communists weren't going to treat them well.
That's why the soldiers went home, took off their uniforms, and tried to present themselves as poor, innocent civilians.
Then the communists took over, and they ran everything. If there was any doubt, you went to a re-education camp.
Can: A day after the liberation, we were ordered to join the force protecting the Independence Palace. On the way, we crossed the Police Department. It was a bit quiet; everything was in order.
People seemed curious about us. They heard rumors that we were weak -- just skin and bones. But they were very calm. Even the haters did not pay much attention to us.
Have your feelings toward the other side changed over the past four decades?
Caron: Oh yeah. You have to understand, it was not unlike our Civil War. "Communist" is a bad word. Were we right to go over there? I don't know. Back in those days, it was the domino theory. If this nation fell under communist rule, then their neighbor would fall.
I thought Thailand would be overwhelmed by communism within a year, maybe two. But I was totally wrong. Thailand and South Korea are just wonderful examples of how successful capitalism can be.
Can: It has been 40 years. And... the winner takes it all. I don't think of it as a "historical mission" or anything big. It's more about a family revenge. My father got killed in the Sihanouk Coup in 1970. The Liberation Army came and saved our village. Then all the boys my age (14-15) decided to join the troops as a way to get revenge.
When the war ended, I immediately got back to normal life. I just tried to raise my family. I put myself out of the big things. I haven't thought of the other side since; just my family.
Do you think the world has a proper understanding of the war and the sacrifices you and your generation went through?
Caron: Absolutely not. History is going to pass some of us on by. Is that wrong? It's not wrong, but it's sad.
Some people say it was wrong. We should have never been there. But then you think, 50,000 people were killed. Hundreds of thousands wounded and injured.
I had a hard time. The government has decided that my heart attack is also very possibly the result of Agent Orange, so now I'm on disability. They did a quintuple bypass, so I'm hanging around.
Can: The media says a lot about the war and our sacrifices every year on the anniversary. But I myself haven't told them about what I have done in the army; not even my family, relatives and neighbors.
Even the local officers don't know much about me except for the fact that I'm a retired soldier. They didn't know about my flag-raising moment, until a reporter came to my house two years ago. I prefer a normal life.
Is it true that in Vietnam, the conflict is called the American War and April 30 is referred to as the Liberation of Saigon?
Can: Yes, we call it "The resistance to America," and the "Liberation of Saigon" -- or the "Total Liberation of the South Vietnam." On the side of the Viet Cong, we see it as a fight against America. I call it the American War, because to me, the Republic of Vietnam and America is one.
In Vietnam today, the conflict is referred to as the American War, and April 30 is called the Liberation of Saigon. How do you feel about this?
Caron: Well, it's not wrong. They have every right to feel like that. We were the nasty invaders, so to speak. I can't agree, because we thought we were doing the right thing.
We were so convinced of the domino theory that we thought we had to do everything possible to stop communism where it was. We were deathly afraid of Russia. By that time, China was communist.
They had every right to be upset with us. I can't condemn them for that. But their brutality, when it came to killing elders and leaders in the villages was unforgivable. For that, I dislike them intensely.
Do you agree with the way the history of the Vietnam War has been told, especially in/by the U.S.?
Can: Once again, the expression "the winner takes all" applies here. We had the victory. Our history writers have their own power to tell the stories in their own way. On the other side, they have their own view points, too. Of course, everyone knows there will be some made-up stories, whatever side it is.
Is Vietnam a better place today for having won the war? What do you think the country would've been like had things gone the other way?
Can: To me, yeah, it is better. We have food, we do not have to think too much about daily aid. The government does what they do, but the people do not know much of it.
Without the events of 1975, Vietnam now would be another version of (South) Korea. I can say that Capitalism means "rich." Forty years ago, Saigon was "The Pearl of Orient." But now, we are 10 years, 20 years behind Thailand. The Pearl seems to be rough now.