MILWAUKEE (AP) — Milwaukee police are responding to what they are calling a “critical incident” on the Molson Coors Brewing Co. campus amid reports of a possible shooting.

WISN-TV in Milwaukee reported Wednesday that a Molson Coors employee received an email about an active shooter near one of the buildings.

Molson Coors spokesman Martin Maloney said there was an “active situation” but didn’t have any further details. There was a heavy police presence in the area, along with fire trucks and ambulances.

Live video showed an officer in body armor getting an assault rifle out of car.

Milwaukee Mayor Tom Barrett also arrived on the scene.

The incident occurred at a sprawling complex that includes a mix of corporate offices and brewing facilities. At least 600 people work at the complex.

Milwaukee police asked that people stay clear of the area and that no helicopters or drones be flown over the site for “officer safety purposes.”

James Boyles told he Milwaukee Journal Sentinel that his wife, Lasonya Ragdales, works at Molson Coors in the claims department. She was texting from inside the building and told her husband that there was active shooter and she was locked in a room with a bunch of co-workers, the Journal Sentinel reported.