Investigators are still trying to figure out how chemicals spilled on the Georgia Tech campus.
Firefighters and HAZMAT crews were called to Tech's College of Computing Thursday night. The building also houses Chemistry and Biochem labs.
Two very dangerous chemicals spilled creating a toxic gas, forcing firefighters to evacuate the building.
Atlanta fire officials said emergency crews were able to neutralize the spill around 9 p.m.
"We were freaking out. We were like 'Oh my God. Are we going to die,'" said freshman Elizabeth Warden.
Warden was there during the incident and heard a fire alarm. At first she thought it was a drill.
"A girl was running down the hall and saying 'You have to get out now. This is not a drill, said Warden.
Georgia tech said it isn't exactly clear just how it happened. Georgia Tech spokesman Matt Nagel said around 7 p.m., grad students were preparing for a lab class.
Someone made a mistake, Nagel said, during normal procedures and the chemicals spilled.
In a written statement Nagel said two incompatible chemicals were inadvertently mixed in a container producing a strong irritant.
Nagel said he didnt know what chemicals were involved.
The building reopened Friday morning. No injuries were reported.
Nagel said three people were taken to Grady Memorial Hospital for observation.
The spill is under investigation.
Copyright 2009 by cbsatlanta.com. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.