Nearly a century after one of the most horrific episodes in American history, the city of Tulsa, Oklahoma, may soon be getting insight into a crime scene that was never fully investigated.

"This is blood land, this was a sacred space where people were burned alive," said Rev. Dr. Robert Turner. "The Greenwood District is not just a tourist site, it's a crime scene."

Turner leads the only African-American church in the Greenwood area that was left standing after the infamous 1921 Tulsa Race Riot, which destroyed one of the nation's wealthiest black communities. But Vernon Chapel A.M.E. Church, he said, was not left unscarred by the violence that took place on May 31, 1921.

"We have the only building that survived the massacre," Turner said — but he added, "we have members who died on that day."

An exterior view of Vernon A.M.E. Church. Rev. Dr. Robert Turner

A 2001 report by an Oklahoma commission dedicated to the event shows that the rampage was sparked by an incident when a black shoe shiner tripped over a white elevator operator and was accused of sexual assault of the 17-year-old girl.

Shortly after news broke out of the alleged assault, a white lynch mob was formed around the jail where the shoe shiner was being held. That prompted a group of armed black men to offer their services to protect the inmate, and it wasn't long before a confrontation broke out between a black and white man that led to an accidental shot being fired.

This signaled the start of a gunfight that would eventually stream into Greenwood as a white mob entered the city and destroyed much of its property.

Buildings and homes were burned and looted, and what was left of what was a bustling financial district — which Booker T. Washington and others called "Negro Wall Street" — looked charred and dismal. While accounts vary, the report estimated 30 to 300 deaths and the displacement of a majority of the town's black residents.

The tragedy has loomed over the town for several years since. First in silence, then in murmurs and now, in outright conversation. The history of the tragedy, Tulsa councilwoman Vanessa Hall-Harper said, has only recently been openly talked about due to many years of "taboo," "fear" and "shame."

But conversations surrounding the decades-old massacre are only set to expand as Tulsa Mayor G.T. Bynum announced via Facebook this week that he would be opening up an investigation into the existence of mass graves from the massacre.

Tulsa's African-American district burns in 1921. Courtesy Department of Special Collections / McFarlin Library/University of Tulsa

The investigation will look at Newblock Park, Booker T. Washington Cemetery and Oaklawn Cemetery, all sites which the 2001 report said indicated "the greatest potential for mass graves within the Tulsa city limits."

"All Tulsans deserve to know what happened in 1921 — especially the descendants of victims," Bynum wrote. "This is a matter of basic human decency."

The Republican mayor said he started researching the existence of mass graves when he was a councilman in 2012. He and another council member eventually reported their findings to the city, but said they never saw anything come from it.

Since then, Bynum said he made a promise that he would launch an investigation should he ever become mayor. But Bynum took office in December 2016, and he only publicly announced plans after Turner had confronted him about it on Tuesday at a community luncheon, according to both Bynum and Turner.