"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," the email read. "Lay down on the floor, and remain as quite as possible. Evacuate the facility only if you deem this safe or necessary." Employees working at Four Times Square received the email, too.

But there was no shooter. Soon after, the department apologized in a second email: "Conde Nast Security Operation Center apologizes for a message received initially of reports of an active shooter at 750 3rd avenue. The message was sent in error. It was a department drill. Please accept our apologies. Please disregard."

Update 4:40 p.m. A spokeswoman for the company emailed a statement to the Media Mob: "The alert was a routine security drill that was mistakenly sent to a broader distribution."

CORRECTION: Due to stupidity, an earlier headline of this item read 'Shooter at Four TimesSquare.' The email from Conde Nast security was about the Fairchild Building on Third Avenue. We regret the error.