At least 7,000 bodies could be buried on the University of Mississippi Medical Center campus, officials have estimated.

The bodies are former patients of the state’s first mental institution and underground radar revealed that their coffins stretch 20 acres across campus where the school wants to develop, The Clarion-Ledger reported Saturday.

School officials have ran into an issue in exhuming the bodies: cost. The newspaper reported that it could cost $3,000 to exhume and rebury each body, an effort that could cost up to $21 million.

The school is looking for cheaper alternatives in handling the exhumations possibly bringing down the yearly cost to $400,000 over the next eight years. The school is also looking at possibly creating a memorial for the bodies and opening a visitors center and a lab to study the remains, the paper reported.

“It would be a unique resource for Mississippi,” Molly Zuckerman, an associate anthropology professor at the school, told The Clarion-Ledger. “It would make Mississippi a national center on historical records relating to health in the pre-modern period, particularly those being institutionalized.”

The Insane Asylum was completed in 1855 to move the mentally ill from chains in jails to better living conditions, though life in the institution remained harsh. The newspaper reported that of the 1,376 patients who were admitted between 1855 and 1877, more than one in five patients died.

The facility eventually moved in 1935 to its present location of the State Hospital at Whitfield. School officials discovered 66 coffins in 2013 while starting constructing a road on the campus.

By 2014, 1,000 more coffins were found when the school was constructing a parking garage. School officials now believe there are Around 7,000 coffins in the area.

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