Laurie, who worked as an Asia correspondent for NBC News and ABC News, also taught broadcast journalism at the University of Hong Kong from 2005 to 2012.

What follows is an excerpt from the The Last Helicopter, which is available on Amazon.com.

April 12, 1975

The end, when it came, came with unexpected suddenness.

Back in Phnom Penh for only a short time, I had been preoccupied with filing daily news reports on a worsening situation. The war, after five bitter years, closed in. I could see it coming and yet I didn’t. The end was near. Yet certainly defeat could be delayed by a few weeks or maybe a few months. The airport remained open. American supplies continued to flow in. Only yesterday, C-130 cargo planes performed another round in their daily airlift from Thailand. I had been out to the front line north of the city. The line was holding. The Cambodians continued to fight, beating back repeated assaults by the Vietnamese-trained, radical Khmer Rouge communists.

I wasn’t ready for defeat, and neither were the Cambodians I knew – most especially the woman with whom I had developed love, intimacy, and friendship five years before.

Sinan, though she had multiple opportunities, would not leave.

I promised her that whatever happened, when the time came, I would get her out. Well, the time had come. And Sinan was not with me. I had left her behind.

I looked out the tiny window of a US Marine transport helicopter as it flew higher over the city. It banked right, heading towards the Gulf of Thailand. Phnom Penh’s lush, pagoda-dotted terrain disappeared quickly beneath me.

Washington had ordered out American diplomats, military attachés, and journalists. A vote by Congress refusing further economic or military support had ensured the death of a nation. The president had run out of options. For America, the war was over. No further assistance for Cambodia would be forthcoming. I was on my way to an aircraft carrier. The Cambodian army would have to go it alone, without the means to succeed. They would certainly, I thought, see it as a final, deadly American betrayal.

I turned away from the window. I couldn’t get the thought out of mind. I had left her behind. I tried to get her out. But I had left her behind. For a minute I buried my head in my hands.

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I looked around. Other men, a few hardened military officers I recognised from the US embassy, had done the same, heads bowed as if in prayer or in mourning. One diplomat was sobbing.

“We left a lot of good Cambodian people behind today,” the man next to me shouted over the roar of the aircraft engine. “I don’t know what’s going to happen to them. It won’t be good!”

On the ground, only a block or two from the embassy, it was already not good. On the night of April 11, Sinan watched as the rescue helicopters pulled away and disappeared over the tree line.

I stood on the sidewalk, within sight of the embassy building. I could hear the extremely loud noises of the helicopters. They were flying northwest to southeast over the city. All this commotion and yet there were no rockets falling, no enemy attack. Why was this happening?

Still, I remembered what Jim had said. “When the Americans decide to leave, they will do so quickly. You must be ready to go. I will take you out. But you must let me know where you are at all times.”

But Sinan was not ready, and she had not told me where she was going after dinner that night.

I walked along the Avenue of Liberty. I saw a Cambodian woman I knew standing on the street. “The embassy,” she shouted to me, “is leaving. Leaving Cambodia!”

As the helicopters flew overhead, a crowd gathered across from the embassy remained calm. They were not anxious to leave. They even joked about how panicked the Americans must be.

Those “Yankees” jumping wildly into their trucks, waving their guns around, in such a hurry to leave.

I looked to the sky. I could see helicopters coming and going. And then they were gone.

As they left, a deadly round of artillery fire crashed into the area on the east side of the Mekong River held by communist forces.

Sinan slowly made her way back to her apartment on the city’s busiest main street. Boulevard Monivong, normally packed with people returning from the Central Market or setting out for a weekend meal in one of the many restaurants, was nearly empty.

Inside her apartment, Sinan positioned herself next to the window. She closed the shutters, squatted down to peer through the slats and waited.

I tried to come to grips with my new situation. Jim was gone. Most of my Khmer friends had gone to stay with their families. I was left very much alone in my apartment. After an hour or so I dried my tears and calmed down.

At 8am I turned on the radio. I always used my small battery radio to hear the VOA, the Voice of America, or sometimes the radio station over in Saigon. The broadcast said that helicopters carrying Americans and some Cambodians had completed their mission and had landed on an aircraft carrier in the Gulf of Thailand. I also heard the war next door in Vietnam was going badly.

My head was filled with a mixture of sadness, loneliness, and fear.

Phnom Penh hung on for four more days … The army fought and then ran out of ammunition. Soldiers deserted to find their families. The defensive perimeter shrank to nothing.

On Thursday morning, April 17, young soldiers marched into the city. Phnom Penh and soon all of Cambodia came under the control of one of the world’s most radical communist movements – the Khmer Rouge. One of history’s greatest episodes of genocide was about to begin.

At first, Sinan refused to obey the new regime’s evacuation orders. Ignoring warnings, ignoring threats, she stalled. She delayed. She tried to prepare.

She carefully observed her surroundings. She began to learn more about the radical communists.

As the Khmer Rouge consolidated their control, she remained, hiding out in her apartment after everyone else had gone.

But as Sinan put it, “On Sunday morning, April 20, there was a sudden change in my situation.”

The Khmer Rouge began a door-by-door inspection to see if everyone had obeyed their evacuation orders. One by one they began breaking down people’s doors. They used either rifle butts or large pieces of heavy metal.

We were very good at locking things. But the communists were even better at breaking things.

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I remember their speech on the loud hailer: “Trust us! We will take care of your homes and your belongings. Just leave. It is dangerous to stay. Americans will bomb you here as they have already done all over the countryside.”

It was noon. Soldiers searched each apartment. They went door-to-door.

I retreated to the small kitchen at the back of my apartment. I heard them try to open my door. It was locked from the inside. They walked away. They were laughing.

My heart beat irregularly. I stood in the kitchen and prayed to Buddha and my ancestors to help me. They passed by my door again. A soldier said, “Let’s try this door, one more time.”

A scrape of metal. My door still did not open. Then I heard a gunshot.

They shot the bolt lock which had kept the steel door shut from the inside. The door opened.

The soldier said, “No matter how strong the opposition, the spirit of the revolution will always win.”

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I remained in the kitchen. I did not know now where to hide. I went behind the curtain which separated the main room from the sleeping area. I was shivering in the heat of my apartment. I turned pale.

A few minutes later, they walked boldly in, opened the curtain, and found me – shaking, cowering on the floor, leaning my head against the bed.

Two soldiers pointed rifles at me. I was in that world just between life and death. I put my hands together in a beseeching gesture.

One young soldier shouted, “Enemy, enemy, hiding herself!”

I prayed to them, asking for forgiveness.

They shouted again, “Put your hands down. Don’t pray to us. There is no prayer in revolution.”