New York (CNN) -- Employees in one of Conde Nast's New York offices got quite a scare on Friday afternoon when a security alert e-mail was accidentally sent out indicating that there was a shooter in the building.
The company was conducting a routine security drill when an e-mail saying a firearm had been discharged on the 10th floor of the 750 building on 3rd Avenue was mistakenly sent to a broader group of people than intended, spokeswoman Susan Portnoy said.
Within "minutes" of the initial e-mail, a follow-up was sent out stating that it was a false alarm, Portnoy said. That second e-mail stated the first message "was a department drill that should have remained internal. Please accept our sincerest apologies."
Friday afternoon, Conde Nast employees received an e-mail which read, "We have received reports that a firearm has been discharged on the 10th floor of 750 building, 3rd Avenue in New York. If you are in a safe location, remain where you are. Get behind a locked door, or hide behind some type of obstruction. Lay down on the floor, and remain as quite as possible. Evacuate the facility only if you deem this safe or necessary."
Portnoy could not say how many employees received this e-mail.
CNN spoke to an employee, who did not want to be named, in the 3rd Avenue building who said that the alert about the shooter in the 3rd Avenue building only went out to employees at Conde Nast's 4 Times Square building.
According to the employee, employees at the 3rd Avenue building only found out about the alleged shooter in their building after co-workers at the 4 Times Square building texted them to see if they were all right and then forwarded on the e-mail alert.
At that point, 3rd Avenue employees took steps to protect themselves.
"Everyone on the floor got up and we all went into a room and huddled together and locked the door," the employee told CNN. "We were crying and everyone was on the phone with their families. We were in the room for about 4 minutes, but it seemed like forever."
The employee and co-workers left the room after someone received a phone call telling them it was a false alarm. After the incident, many people left work early.