The Tulsa Race Massacre Centennial Commission on Thursday canceled an event for Memorial Day that was slated to include Stacey Abrams and singer John Legend.

Organizers in Oklahoma cited “unexpected circumstances with entertainers and speakers” in making the announcement, saying a similar event might take place later this year, but offered no details.

“We apologize for the disappointment and any inconvenience caused to ticket holders; if rescheduled ticket holders will be notified first,” organizers said in a statement Thursday.

Tickets for the event were snatched up in just 30 minutes after they went on sale earlier this year.

The commission is still planning to hold other events marking the 100th anniversary of the burning of Black Wall Street and dozens if not hundreds of deaths.

President Biden is scheduled to visit Tulsa on Tuesday.

Organizers said even though Monday’s main event is canceled, they’re hopeful that the national attention around the anniversary will help shine a light on the massacre and its legacy.

“This moment is a moment to face that horrific incident that happened back 100 years ago and bring it to today to say, ‘We still haven’t solved race relations in America and it’s time,’” said commission chairman Kevin Matthews, a state senator who spoke to The Hill before the cancellation of Monday’s event.

Black Wall Street was a thriving community in the early 20th century located in downtown Tulsa, spanning a 35-block business district.

According to the Greenwood Cultural Center in Tulsa, it was “the richest African-American neighborhood in North America” at the time.

“It was a thriving area and the money circulated inside its own community,” said Larry O’Dell with the Oklahoma History Center. “They were spending money at their own businesses because they couldn’t spend it anywhere else.”

On May 30, 1921, that all changed after a young Black man named Dick Rowland used an elevator in a downtown Tulsa building to get to a “colored” restroom. The elevator operator was a young white woman named Sarah Page.

“When the elevator reached the first floor, a clerk heard Page scream and saw Rowland run out of the building. The clerk reported the incident to the police,” according to the Oklahoma Historical Society.

The May 31, 1921, edition of the Tulsa Tribune newspaper ran a headline of “Nab Negro for Attacking Girl in Elevator,” which historians believe was one of the factors that ramped up the ensuing violence. Many white residents believed, without evidence, that Rowland had assaulted Page.

Thousands of Black-owned businesses were burned to the ground, and historians still don’t have an accurate count of how many lives were lost.

According to the Tulsa Historical Museum and Society, more than 800 people were treated for injuries. Initial reports put the number of deaths at 36, but the museum said historians “now believe as many as 300 people may have died.”

There is an ongoing mass grave search in an attempt to get a more accurate count.

Michelle Place, who serves as the executive director of the Tulsa Historical Society and Museum, said that while the photos from that day are “horrific,” it’s important to view them to begin to comprehend what happened.

It “seemed like an atomic bomb had been dropped in Greenwood,” Place said.

The Greenwood Cultural Center said the Tulsa Race Massacre is “to date, still the single deadliest and most destructive act of racial violence and domestic terrorism in United States history.”