A false alert that warned of an active shooter at Hudson Yards and was sent to employees of a building at the complex prompted a brief panic Wednesday before the New York Police Department said the message stemmed from a training exercise.

The NYPD confirmed the alert related to 31 Hudson Yards, a tower that houses the headquarters of the Equinox Group and other commercial space. Social media posts from people who said they worked in the building described alarm and anxiety after receiving the message; one X user wrote, "We just had an active shooter scare at my office, holy sh-t my heart is still pumping."

Police said the alert ultimately turned out to be part of a training exercise conducted at the site. The NYPD did not say whether the notification prompted an on-scene emergency response or provide details about who authorized the exercise or why the message was distributed to employees. It also was not immediately clear what mechanism delivered the alert to staff or whether the system involved was internal to the building or part of a wider municipal notification network.

The Equinox Group, which operates a fitness center and a hotel at the Hudson Yards location in addition to corporate offices, did not immediately respond to requests for comment. Building occupants and workers at the mixed-use development said the notice caused temporary confusion and fear as employees sought confirmation from management and one another.

Hudson Yards is a major Manhattan complex with offices, retail, residential units and public spaces. Large commercial buildings and corporate campuses periodically conduct drills and exercises intended to prepare staff and first responders for emergencies. Officials have not detailed whether this particular exercise followed a planned schedule or whether any safeguards were in place to prevent a training notification from reaching employees as if it were a real incident.

The NYPD statement confirmed the training designation but offered few additional specifics. City agencies and building operators typically review drills and emergency message protocols after incidents when false or unintended alerts are issued; the outcome of any such review in this case was not immediately available.

Employees and tenants who experienced the alert said they were left shaken but relieved once authorities clarified the situation. No injuries or reports of violence were disclosed in connection with the notification.