Now I am become Death, the destroyer of worlds

From Robert Oppenheimer in an interview in an NBC television documentary The Decision to Drop the Bomb (1965), produced by Fred Freed. I have heard and seen reference to this quote dozens of times and knew it was from Oppenheimer but never knew the source context. Oppenheimer is speaking of the Trinity nuclear test, the first nuclear explosion.

We knew the world would not be the same. A few people laughed, a few people cried, most people were silent. I remembered the line from the Hindu scripture, the Bhagavad-Gita; Vishnu is trying to persuade the Prince that he should do his duty and, to impress him, takes on his multi-armed form and says, "Now I am become Death, the destroyer of worlds." I suppose we all thought that, one way or another.