Work on a $70m high school in northwest Chicago is to go ahead on a vast, forgotten cemetery used by an insane asylum and a poor house that may hold as many as 40,000 corpses.
But construction workers will be given instructions on how to handle human remains.
In the 19th century the plot in the Dunning neighbourhood housed the Cook County Poor House as well as a hospital for consumptives and an insane asylum.
Together, these institutions used a 320-acre graveyard between 1854 and 1912, which the city of Chicago lost track of during the 20th century.
The existence of the graveyard between Irving Park Road and Montrose Avenue was suspected in 1989 after bodies began to be dug up during foundation work on a condominium.
Work on the 1,200-pupil three-storey school can go ahead, but workers will be armed with ground-penetrating radar and a five-page booklet setting out the protocols to be followed when uncovering human remains.
The Cook County Poor House was open between 1855 and 1912 (NW Chicago Historical Society)
Curbed Chicago reports that these include instructions are rules on removing "coffin hardware and associated grave artefacts". Human bones will be placed in plastic boxes, after which the contractor and the state agencies will decide on a final resting place.
The project is due to be finished by the autumn of 2019.
In 2014 a database was published that listed the names of 8,000 Chicagoans who were buried in the cemetery.
This was compiled by Barry Fleig, 70, the former cemetery chairman of the Chicago Genealogical Society historian, who found the names by combing contemporary records.Â
A radio broadcast on the poor house, entitled "Tomb for the Living", can be heard here.
Top image: The Dunning memorial park where some of the dead are buried (Creative Commons)