Construction has been halted at the Obama Presidential Center in Chicago after a noose was discovered on site, reports NBC News.

Law enforcement officials responded at approximately 4 p.m. to a call that a noose was hanging in a stairwell at the site.

According to the Anti-Defamation League, a noose is identified as a hate symbol against African Americans and brings up memories of the thousands of lynchings that Black people endured in the U.S.

"Violence or threat of violence replaced slavery as one of the main forms of social control that whites used on African-Americans," the ADL said.

"This shameless act of cowardice and hate is designed to get attention and divide us. Our priority is protecting the health and safety of our workforce," the Obama Foundation said in a statement. "We have notified authorities who are investigating the incident."

The center will commemorate and preserve artifacts from President Barack Obama's two-term presidency and will include "a museum, a plaza, a rooftop garden, and a new branch of the Chicago Public Library." In September 2021, the center held its groundbreaking; it is expected to open in 2025.

The Obama Presidential Center is led by Lakeside Alliance, in a joint venture between four Black-owned construction firms— Brown & Momen, Powers & Sons Construction, Safeway Construction and UJAMAA Construction—and Turner Construction, the primary contractor.

Lakeside Alliance is offering a $100,000 reward for any information that leads to the capture of the suspect.

“We have zero tolerance for any form of bias or hate on our worksite. Anti-bias training is included in our onboarding process and reiterated during site-wide meetings,” the alliance's statement read. “We are suspending all operations onsite in order to provide another series of these trainings and conversations for all staff and workers.”

Responding to the incident, Chicago Mayor Lori Lightfoot said, "Racism and racist symbols have no place in Chicago."