Investigators have discovered 21 coffins in unmarked adult graves that could be connected to the victims of the 1921 Tulsa Race Massacre, reports NPR.

Last Monday, city officials of Tulsa, Oklahoma, announced that 17 adult-sized graves were exhumed from an excavation site in the Oaklawn Cemetery and four more were found on Tuesday, including two child-sized burials.

The project is part of the city's efforts to get an accurate count of how many people were killed when a white mob destroyed the affluent Greenwood district of Tulsa over 100 years ago. The incident was one of many race riots that took place in 1919, which is also known as “Red Summer.”

State archeologist Kary Stackelbeck stated that scientists will now have to excavate the site by hand using finer-grain tools to clean up the coffins. This process will help researchers analyze the style of construction and specific hardware of the caskets in order to determine when they were first buried.

“This is going to be part of our process of discriminating which ones we're going to proceed with in terms of exhuming those individuals and which ones we're actually going to leave in place, at least for now," she said.

In 2021, researchers discovered 19 unidentified bodies that later received a proper burial.

"But testing on some did not yield a very good result," Stackelbeck said in an update she gave in October.  She explained that research teams will return to the same bodies to "obtain some additional samples and hopefully get some better results."

"Much like last year, we're trying to do every step of this process as respectfully as possible," she said.

The excavation project is expected to be completed by November 18, 2022.

Over a hundred years later, descendants of the victims along with community organizers have been honoring the legacy of Black Wall Street and seeking justice on their behalf. In June of 2021, thousands visited Tulsa to commemorate the race massacre that destroyed the thriving Black metropolis  Celebrities, politicians, and family of the deceased paid their respects to the hundreds who were victims of one the largest race riots in U.S. history. Back in August, an Oklahoma judge ruled that the three known survivors of the attack can proceed with their lawsuit.

District Judge Caroline signed the order that allows Wall Lessie Benningfield “Mother” Randle, 106, Viola “Mother” Fletcher, 107, and Hughes Van Ellis, Sr., 101, “to continue seeking reparations under state nuisance laws.”