A century later, city still struggles with slaughter

Abutting downtown Tulsa, "the Greenwood District is in essence black mainstream for those unable to participate in the white-dominated economy", said Johnson.

One accidental result of the segregation was that wealth created by the black Tulsans had nowhere to go but to stay within the 35 blocks, in the form of 200 black-owned businesses and many affluent families that had among them black millionaires. The discovery of oil and natural gas, which led Tulsa to become the self-proclaimed "Oil Capital" starting from the 1910s, also contributed to the phenomenon.

Greenwood became the talk of the nation, a model of black cooperation and economic independence, and a beacon for all African Americans, especially those from the racism-marred Deep South. Yet it was also "an anomaly" to quote Johnson, one that "thrived at a time when the Ku Klux Klan was incredibly active in Oklahoma", dodging bloody white-on-black violence that had erupted across the US in what's known today as the Red Summer of 1919.

"All it needed was a sort of match, an igniter tossed on the embers," said Johnson.

That triggering event took place on May 30, 1921, and involved two teenagers — Dick Rowland, a 19-year-old black shoeshine worker, and Sarah Page, a 17-year-old white girl who ran an elevator in the Drexel building in downtown Tulsa.

"The boy went to the building, boarded the elevator, something happened, and Sarah Page began to scream. They both ran out of the elevator," said Johnson. "What happened there we'll likely never know. But the next day, Rowland was arrested and taken to the court."

That same afternoon, the white-owned Tulsa Tribune newspaper ran a highly inflammatory article with the headline "Nab Negro for Attacking Girl In an Elevator", accompanied by an editorial titled "To Lynch Negro Tonight" — something that a white mob immediately sought to do, by gathering on the lawn of the city courthouse, where Rowland was in jail on the top floor, and demanding his handover.

Outside the courthouse, the white mob clashed with a group of black people who marched down there to protect Rowland and make sure he received a trial. A shot was fired and "things sort of went south from that point", said Johnson.

Armed and greatly outnumbering the black group, the white mob shot its way through the Greenwood District, firing indiscriminatingly into businesses and residences. That was followed by looting and burning, which lasted for 16 hours until noon June 1. The assault was even assisted by the use of private planes, with attackers either shooting from the plane or dropping incendiary devices onto the buildings.