FREDERICKTOWN — Tornado sirens have caused some nervousness around Fredericktown this week, starting with an unplanned wake-up call around 10:30 Sunday night.

The siren at the Senior Citizen Building on East Sandusky Street began sounding, and several residents called the 9-1-1 dispatch centers at the Knox County Sheriff’s Office and the Mount Vernon Police Department to find out if a tornado was really on the way, or if the siren was malfunctioning.

“There were lots of calls,” said Marie Blubaugh, Knox County Emergency Management Agency director.

There were no weather warnings issued Sunday night, and the siren had not been set off by the county. Personnel at the KCSO were unable to turn off the siren because the siren had not been initiated by the KCSO.

Fredericktown Police Chief Jerry Day went to the Senior Citizen Building to check the siren, and was able to manually override the system and turn it off.

Day said that a switch on the outside of the siren had been activated manually by an unknown person or persons.

“That won’t be a problem anymore,” Day said. “We’ve taken care of it.”

The siren can no longer be activated from the outside.

The siren was tested Wednesday morning, according to Blubaugh, and is working fine. Also tested Wednesday was the old siren at the Fredericktown firehouse. Inactive for about 16 years, it has been put back into service as a tornado siren.

“It will give more coverage to the individuals in Fredericktown,” Blubaugh said.

The firehouse siren was installed when the firehouse was built in 1980, and used for years to alert volunteer firefighters in the event of a fire call. Blubaugh said the old fire siren at the Howard substation of the Eastern Knox County Joint Fire District has also been given a new life as a tornado siren.

The 17 tornado sirens across the county can be set off at the KCSO or the MVPD; each siren is tested on the first and third Friday of each month at noon, according to Blubaugh.

Fredericktown residents should be aware that because the tornado sirens were already tested this week and found to be in working order, they may not be tested Friday because of the holiday.

“All the sirens in the county are designed to be heard out-of-doors,” Blubaugh said. “We do recommend every homeowner buy a weather radio if possible.”