The count of how many workers died varies. According to congressional testimony at the time, as many as 300 people died from silicosis, caused by exposure to silica dust. Cherniack estimates the number to be at least 764 workers — including Flack.
"They would become sick, profoundly short of breath, have severe weight loss, basically be unable to move and function and exercise themselves," Cherniack says.
Flack died on May 20, 1931, two weeks after his last shift in the tunnel. His death certificate says he died of pneumonia, but according to Cherniack, company doctors often misdiagnosed worker deaths or attributed them to a disease they called "tunnelitis."
The company would later use those death certificates to prove there were few, if any, silicosis deaths at the tunnel.
"They never knew the real truth"
Hundreds of local white men worked in the tunnel alongside black migrant workers like Flack, but conditions were even worse for the more than 2,000 black men, who made up the vast majority of the workforce.
Black workers who testified before Congress in 1936 said they were denied 30-minute breaks in clean air. They said if they got sick, supervisors would force them from bed at gunpoint.
According to death certificates, black workers were often buried in unmarked graves. In some cases, there was no attempt to notify the victim's family, according to Watts.
But NPR did find one relative: Sheila Flack-Jones of Charlotte, N.C., who is Dewey Flack's niece.
I'm heartbroken that my family died thinking that he had run away and they never knew the real truth.
Sheila Flack-Jones, whose uncle died from silicosis after working in the Hawks Nest Tunnel
"My father mentioned when I was younger that he did have a brother but the brother he thought had run away," Flack-Jones says of learning her uncle's fate. "I'm heartbroken that my family died thinking that he had run away and they never knew the real truth."
Five years after Flack and over 700 others began to contract silicosis, the U.S. House of Representatives Committee on Labor held a hearing on the Hawks Nest Tunnel disaster. Representatives from the tunnel companies declined to attend. One submitted a letter that called witness testimony "slanderous rumors and hearsay."
"We know of no case of silicosis contracted on this job," the letter concluded.
The congressional committee said the tunnel was completed with "grave and inhuman disregard for all consideration for the health, lives, and future of the employees."
Congress took no action against the companies, but that same year it passed a law requiring the use of respirators in dusty working conditions.
More than 500 lawsuits were filed against Union Carbide and a contractor, Rinehart & Dennis, many of which were settled out of court.
Dow Chemical, which purchased Union Carbide in 2001, did not respond to NPR's requests for an interview.
"Historical amnesia"
Adelina Lancianese
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