WI – At least four people were taken to a hospital Thursday night after apparently being overcome by carbon monoxide at a plant.

The Calumet County Sheriff’s Department said Brillion police, Brillion firefighters and Gold Cross Ambulance were called to the Ariens Co. Plant 3, 1555 Ryan St., about 8 p.m. on reports that employees were becoming nauseated and faint.

Employees were outside the plant when emergency crews arrived, officials said.

County dispatchers said at least four people were taken to St. Elizabeth Hospital in Appleton with apparent carbon monoxide poisoning. Police Capt. Dan Alloy said a plugged filter caused exhaust from a paint booth to vent into factory.

The plant was closed for the night. Alloy estimated a couple hundred people had been evacuated.