“There was no plausible way for a worker to accidentally fall into the vat.” So writes Amber Hunt for the Cincinnati Enquirer in a lengthy piece about the 1984 death of David Bocks. He worked—and died—at Ohio’s Fernald Feed Materials Productions Center, whose bland name masked the secretive work that was done there: the refining of weapons-grade uranium. Bocks worked the midnight to 8am shift maintaining the plant’s pipes. He went missing during his June 20, 1984, shift, and his whereabouts remained a mystery for several days, until the NUSAL vat was drained. The 4-by-10-foot vat housed a lava-like “slurry” of sodium chloride and potassium chloride heated to a consistent 1,350 degrees and used to mold uranium pieces called ingots. In the hardened slag were chunks of bone … and Bocks’ locker key.

The death was ruled a suicide. Bocks had been diagnosed with schizophrenia nearly 10 years prior, but had been taking his medication as prescribed at the time of his death. His manager described him as in low spirits during his final shift and having eaten an extra sandwich, suggesting a sort of “last meal.” But the vat’s opening was small, “essentially the size of two sheets of notebook paper taped together length-wise,” writes Hunt. That Bock, who was 6-foot-1 and weighed between 180 and 200 pounds could have fit in there was disputed by some. And the vat registered two temperature dips over a 15-minute span, leading his kids to speculate he was murdered—perhaps because he was aware of safety issues at the plant, or due to a recent clash with a co-worker—and placed in the vat in two pieces. Hunt’s full piece gives way more detail on the case; read it here.