WLBT reports that the Historic Natchez Foundation was evacuated Thursday due to the discovery of a chemical.
The Natchez Police Department and federal agencies are testing the substance to see exactly what it is.
According to police, evacuations began around 11 a.m. Thursday.
Officials at the building were doing an inventory of donations when the vials of chemicals were discovered.
Police decided to practice caution and evacuate the building and surrounding streets until they could determine what the chemical was. They evacuated Commerce Street between State and Main Streets as well as Main Street from South Union to Commerce Street.
Emergency Management Director Brad Bradford told WLBT that his agency is waiting on the chemical test results from the national guard.