A suspicious package sent to a biomedical building at Georgia Tech that was thought to contain fentanyl actually contained sugar, officials said Wednesday.

Firefighters were called to the Krone Engineered Biosystems Building on Atlantic Drive at 3:45 p.m. after getting reports of a suspicious package, Atlanta fire spokeswoman Alyssa Richardson said. Fire crews and Georgia Tech police officers evacuated the building.

In a statement, Georgia Tech said staff members opened a letter that was mailed to the building over the weekend. The letter “was threatening” and the fire department said they believed the substance found was fentanyl. Federal investigators later confirmed the substance was not fentanyl.

“With more detailed testing, it turns out it was sugar,” a Georgia Tech spokesperson confirmed.

Hazardous material crews cleaned and cleared the building soon after it was evacuated and an investigation into the letter continues, school officials added.

No injuries were reported, and the six people who were exposed to the contents of the letter prior to officials learning it was sugar all signed patient refusals, Richardson said.

The 200,000-square-foot Krone Engineered Biosystems Building, which opened in 2015, is located near the North Campus Parking Deck off 10th Street. It houses research efforts related to biomedicine and biotechnology and offers lab space for faculty, researchers from different disciplines and students, according to Georgia Tech’s website.

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