Investigators say they do not know what caused a security K9 to trigger an evacuation.
It happened in southeast Austin at a federal office complex.
About 500 IRS employees could be seen Wednesday morning standing outside of the SE Austin complex where they work. The all clear, shortly after 9:30, brought relief and a little anxiety for workers like Daryl Adams.
"I'm a little nervous about going in, but I’m going to go in, and do my job."
The evacuation happened because of concern about something suspicious in a mail cart.
"I believe the IRS contracts with a private company that handles the mail room, they have a K9 dog there that’s trained to alert on explosive material which was the case here,” said APD Spokesperson Bino Cadenas.
The complex was in lockdown while the APD bomb squad and federal authorities searched letters and packages. "I wasn't really that scared or upset, but a couple of my co-workers were stuck in there and they wouldn't let them leave, so I was more worried for them if something were to happen,” said IRS employee Anna Kosta-Rodriguez.
It was determined that there was nothing harmful in the package.
For many long time employees the situation is a reminder of what has actually happened in the past.
"It makes reality come to us, but it’s a, very, protected area,” said IRS employee Jennie McDonald.
Security upgrades were made after an attack, in 2010, near the Arboretum, a man who was upset with the IRS flew his plane into a building where several federal employees worked.
About a dozen people were injured and IRS manager, Vernon Hunter, was killed.
"I was on Texas State when all the Texas University campuses had all those fake bomb threat happen, it kind of brought it back to it, but since this was more of a mysterious package, it’s real, this isn't a threat, it puts you a little bit on edge, but we are in a really secure facility, we feel safe a lot of the time, we were about to go through drills pretty recently,” said Jessica Sahas.
A warehouse for the VA is also on the IRS complex.
The employees there got to go back in before the IRS workers. To help those left outside, an air conditioned warehouse was in the process of being opened when the all clear came.