Researchers say they've discovered as many as 7,000 graves beneath the University of Mississippi Medical Center's campus in Jackson.
The land was part of the Mississippi State Lunatic Asylum until it shut roughly 80 years ago, and experts say the find that was announced at the weekend potentially offers closure for families whose relatives vanished decades ago.
Research teams used ground-penetrating radar to painstakingly detect the suspected patients' remains, buried in coffins, after uncovering 66 caskets in 2012, Dr. Molly Zuckerman, an associate anthropology professor at Mississippi State, told HuffPost.
According to Zuckerman, who is helping carry out excavations with the Mississippi State Asylum Cemetery Project, 35,000 people were institutionalized at the facility from 1855 until 1935.
During the period the center was open, death was far from uncommon among its patients.
"Mortality was very, very high in the [Mississippi State Lunatic Asylum]," Zuckerman said. "Most died 13 months after they were institutionalized."
The common causes of death "shifted through time," Zuckerman said, but "none of them were particularly unusual."
Many patients died of tuberculosis, strokes, heart attack, and occasional epidemics of yellow fever and influenza.
They also died from nutritional deficiencies, including pellagra, which is a vitamin B deficiency, she said.
Those people buried in the asylum's cemetery likely had relatives who couldn't come and claim them or weren't notified of their deaths in time, she said.
People consistently want to know, can you find my ancestors in the records?
Though decades have passed, she said some patients' family members haven't stopped wondering whatever happened to them.
"People consistently want to know, can you find my ancestors in the records?" she said. "Overall, it's just tremendous sadness and curiosity."
Zuckerman said she generally receives two to three emails a week from the descendants of Mississippi State Lunatic Asylum patients that have read about her work.
"Sometimes it's a straightforward exchange, other times we talk on the phone and I get to learn about the story that surrounds this ancestor, this lost ancestry," she said. "It's never a happy story. It's always tragic."
Karen Clark of Clinton, Mississippi, is among those hoping a relative will be found should DNA testing be done on the remains.
Clark discovered that one patient was her great-great-great grandfather, Isham Earnest, who fought in the War of 1812, a conflict between the U.S. and the United Kingdom. Earnest is believed to have died at the facility some time between 1857 and 1859. It followed Earnest being ruled "insane," Clark told the Clarion-Ledger.
"Hundreds, if not thousands, of descendants are here today because of Isham Earnest," she told the local paper. "Many are teachers, nurses, educators and ministers."
Zuckerman said the research team hopes to exhume every coffin uncovered and identify the remains of each person. Researchers plan to create a memorial, visitors center and genealogy research facility that Zuckerman believes would be the first of its kind worldwide.
Exhuming the bodies and creating such a facility, of course, comes with a heavy price.
Zuckerman said the cost of excavation is around $21 million, using an outside contracting firm. The other option would be to use "in house" excavators, she said, which would cost at least $400,000 a year over the course of eight years.
Because the graves are located on public land, she said the state of Mississippi would likely be stuck footing the bill. Other options would be to request private and federal grants. Even so, "a lot of money just might have to come from the state of Mississippi," she said.
Despite the high costs, Zuckerman believes such a facility would be an invaluable resource.
"The people buried aren't just bodies but can be turned into a tremendous resource for living people in the state," she said.
"So that is one of the reasons why the goal is not just to remove them from the ground and rebury them but to turn this into a unique resource."
Ralph Didlake, the director of UMMC's Center for Bioethics and Medical Humanities, also stressed this point to The Washington Post.
"There's a historical stigma associated with mental illness, and that's very true historically, but this is an opportunity for us to deconstruct that stigma by studying that experience," Didlake said.
"How do we look at this through a modern lens and how does all this inform how we take care of mental health issues going forward?"