(CNN)Oklahoma leaders announced Wednesday the state will be moving forward with embedding the story of the 1921 Tulsa Race Massacre into the curriculum of all Oklahoma schools.
On the last day of May in 1921, a white mob estimated at 10,000 people descended on the Greenwood District -- then an affluent black neighborhood in Tulsa known as Black Wall Street -- and burned it to the ground. Hundreds of African-Americans were killed. Hundreds more were unaccounted for.
But that part of history went unmentioned for decades in classrooms across the state.
The killings remained "Tulsa's dirty secret," state Sen. Kevin Matthews said at a news conference Wednesday.
And while school districts have begun teaching about the massacre, State Superintendent Joy Hofmeister said in the news conference, the state's education department will be releasing a curriculum framework this April to bolster those efforts throughout the state.
The framework, Hofmeister said, will give teachers "extra support and resources" when teaching about the massacre.
"What we want to ensure is that ... we are teaching in a grade-appropriate level those facts that have not been taught in a way they should have been taught in Oklahoma," she said. "This is ... our history and we should know it."
Starting this fall, students from elementary through high school will learn about the event, officials said.
Deborah A. Gist, the superintendent of Tulsa Public Schools -- which ran a pilot program teaching the material that's about to go statewide -- said it wasn't until after she got into teaching that she learned about the massacre, despite being a student of the school system she now oversees.
"What I'm deeply committed to in Tulsa Public Schools is making sure that never happens again," she said.
What's changed in 100 years
With the century mark of the harrowing event approaching, Sen. James Lankford said at the news conference that the whole country will soon "pause ... and will look at Tulsa and will ask the question 'what has changed in race relations in Tulsa in 100 years.'"
"It's a reasonable question," he said.
Teaching about what happened is a step toward progress, officials say.
Tulsa Mayor G.T. Bynum said that going forward, the question is "how we can use this horrible tragedy to instruct and inform and make sure that nothing like this ever happens again."
"This isn't something that you just read about in history books and think that's something that happened 100 years ago, it can never happen again," he said at the news conference. "That's exactly what people in 1921 in Tulsa probably thought too."
He said he hopes to see more "black ownership of business in Greenwood and in Tulsa" in the future.
"This is an incredibly important thing for us to have moving forward in our city."