Crews put out a fire at an Appleton hydro plant Monday night. At about 11:15 p.m., the Appleton Fire Department was called to a fire off Olde Oneida and Edison Streets. There was a report of smoke and fire. Crews found fire in the plant located off Edison Street. It took about 30 minutes to get the fire under control. Firefighters stayed on to ventilate the building. No one was hurt. The cause of the fire is under investigation.