Because I finished the bulk of my research while George W. Bush was still in office, I don’t know if the situation has changed under Barack Obama. However, weeks after Obama’s inauguration, I began getting calls from newly placed FOIA administrators who apologized for the delays and promised to fast-track some of my requests. In a few cases, this actually happened. Others sank quickly back into the FOIA darkness.

I finished this project with a mixed sense of hope and hopelessness. My original goal was to unearth every important document about this nuclear accident, to tell the definitive history of the event. I may have succeeded, but I doubt it. In coming years, I am sure that more documents will emerge to further illuminate the story. That, I have come to accept, is the nature of history.

Barbara Moran is a science journalist in Boston. Her first book, The Day We Lost the H-Bomb: Cold War, Hot Nukes, and the Worst Nuclear Weapons Disaster in History, was published by Presidio Press, an imprint of Random House, in 2009.