I began my search by dipping my toes in the water and starting to get grounded. Wikipedia was the first link to pop up so i started there to get a basic understanding of the photograph or photographer, or whatever popped up (taking it all with a grain of salt due to it being wiki of course).
I found that Hugh (as he was oft called) was born in 1941, and died in 2009. An interesting note is that he died in Hong Kong, something I will look into deeper later. Hugh had worked earlier that day taking photos of the people working to destroy documents, and was in the process of developing the film from earlier that day, when a co-worker hollered at him that there was a helicopter on a roof. Hugh then took his famous photo of the evacuation. The bird squeezed on more than it’s max capacity for takeoff, but still left many people behind. The unfortunate ones were still on the roof waiting when the enemy forces arrived. The helicopter shot was developed and released for the 17:00 transmit to his paper.
The building the helicopter left from was not a U.S. Embassy, but rather a CIA outpost in an apartment building. It’s address is 22 Gia Long st in Saigon. Hugh returned to Vietnam for the first time in 1990.
The next piece i found was an article that Hugh wrote for the New York Times on April 29, 2005 (see link). here he narrates some of what happened that day, 30 years ago. Gia Long st was to be the evacuation rally point, and there was an elaborate code that was supposed to initiate the evacuation involving 105 degrees and White Christmas to be played, although it is believed that it was never played. Buses driven by Marines were to take the press out to the airports. Hugh (the last photographer) and a few co-workers decided to stay. Hugh photographed until the first of June when the Vietnamese made it clear to him and all other press that they were no longer welcome.
The last link is a documentary of an interview with Hubert.