ATLANTA - A half-dozen people were exposed to a "suspicious" substance on the campus of Georgia Institute of Technology on Wednesday afternoon.
Atlanta firefighters rushed to the Krone Engineered Biosystems Building located near the corner of 10th and State streets around 3:20 p.m. Once they arrived, firefighter say they located some sort of substance inside a package.
Officials say the letter came in a threatening letter.
"I saw three cop cars a fire truck and ambulance from Grady," said Jameson Phan, who is a student.
University officials say a letter was mailed to the building that was "threatening and had an unknown substance inside."
Atlanta Fire Rescue believed the substance was fentanyl. Six people were exposed to the substance, but seemed fine and refused treatment.
The building was evacuated, and hazardous material crews went in and cleaned the building.
Officials investigate after six people were thought to be exposed to fentanyl at a Georgia Tech lab on June 7, 2023. (FOX 5)
A few hours later, university officials released an update saying the substance was tested by the FBI and postal inspectors and was determined to be sugar and not a hazardous material.
Many students still have a lot of questions about that threatening letter.
"What is the explanation for all of this because it doesn't really make sense," said Breanna Shi, a student who does research in the building.
Georgia Tech’s website lists the Engineered Biosystems Building as a "200,000 square feet of technologically advanced laboratories for faculty, researchers, and students to pursue Georgia Tech’s growing research agenda in the biological sciences."
"The research conducted in EBB helps distinguish Georgia Tech as a national leader in biomedicine and biotechnology," the description reads.
The state-of-the-art facility is a "commitment to improving and saving lives by bringing new treatments, medical technologies, medications, and therapies to patients," the institute says.
University officials are investigating who sent the letter and why. They ask anyone with information to contact Georgia Tech Police.