CNN  — 

A fire prompted the evacuation of the Charlotte-Douglas International Airport tower Saturday in North Carolina, a Federal Aviation Administration spokeswoman said.

Nonessential personnel were ordered out, the FAA’s Arlene Salac said in a statement. The fire was extinguished. The employees returned.

Air traffic controllers handled traffic at a “reduced rate,” the statement said. At one point, the FAA website showed the airport under a ground stop, but that has been lifted.

The cause of the fire is being investigated, Salac said.