April 30, 2015 12:30PM ET by Todd Reed & Michael Okwu – Forty years after Saigon fell, the CIA’s former chief strategist in Vietnam is haunted that more lives weren’t saved

LOS ANGELES – On the morning of April 29, 1975, Bing Crosby’s “White Christmas” blared on the radio. The holiday classic was secret code for the start of the evacuation, dubbed “Operation Frequent Wind,” the largest airlift of its kind.

Those final moments before the fall of Saigon are seared into the memory of Frank Snepp, the CIA’s former chief strategist in Vietnam and one of the last Americans to get out. Snepp says Marine guards beat back the Vietnamese on the rooftop, so he could get a seat on the helicopter.

“It arched up and I could see on the edge of the city 140,000 North Vietnamese troops moving in with the lights on,” said Snepp. “We move out toward the coastline and we suddenly began taking ground fire … and the helicopter pilot wrenched the controls and we gained altitude and got out.”

More than 60 military and Air America choppers took part in the operation. Pilots flew more than 600 flights, airlifting 7,000 people out on that final day, including 900 from the U.S. Embassy alone.

Read the entire story at America Aljazeera