That's the first I heard that.
“On May 30, 1921, Dick Rowland, a young African American shoe shiner, was accused of assaulting a white elevator operator named Sarah Page in the elevator of a building in downtown Tulsa.”
https://www.britannica.com/event/Tulsa-race-massacre-of-1921
I first read of it in a book at the downtown Tulsa County Library back in 1970. So much for a “coverup”. It just was not the most important thing on people’s minds in the years after.