Forty years ago, employees of the National Archives and Records Service experienced the thing they had been working for decades to prevent: some of the highly flammable nitrate-based film held in the federal complex in Suitland, Maryland, had caught fire, the blaze ultimately destroying 12.6 million feet of historical newsreel footage and outtakes that had been donated by Universal Pictures.

The fire broke around lunchtime on December 7, 1978 in the film vaults, as Andrew Smith, a records analyst for the National Archives and Records Administration, recounted this month for the Unwritten Record blog.

The structures, called buildings A, B, and C, had been created specifically to store the fire-prone film in 1945. When Universal agreed to donate its library— a mix of nitrate and acetate footage covering 1929 to 1967—to the National Archives in 1970, other improvements, including a high-speed sprinkler system, were added to the vaults.