This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated.

O’FALLON, Mo. – O’Fallon residents received an unexpected wake-up call Friday after a tornado siren malfunctioned and went off in the wee hours of the morning. And it didn’t stop for quite some time.

Captain Chris Hunt, the Director of St. Charles County Regional Emergency Management, said the malfunctioning siren went off about 4:30 a.m. and continued for around 40 minutes.

The malfunctioning siren, located on Mexico Road between Highway K and Bryan Road, is one of 16 in O’Fallon and 139 across St. Charles County.

The National Weather Service said they received calls from people in the area that said they were hearing the sirens. But the NWS said there was no severe weather in the area and they didn’t issue any warnings.

Hunt said the sirens are tested weekly and this one had not shown any problems until now. Crews took out the siren’s motherboard and took it to be tested. However, they haven’t been able to figure out what caused the malfunction, so the unit is being shipped back to the vendor. It’s unclear how long the repairs on the broken siren might take.

“We do know that it was isolated to this siren. We don’t know if it was struck by lightning yesterday with the storms that moved through the county or if it’s from water but these sirens are exposed to the elements — the boxes are,” Hunt said.

The city of O’Fallon tweeted two hours later “Apparently this was a malfunction. The city does not control the sirens; they are run by the county`s emergency management office.”

A temporary tornado siren has been put up at Rock Creek Elementary School, which is very close to the problem siren. The temporary siren will remain in service until the siren that malfunctioned in fixed.

Even with the problem, Hunt said he remains 100 percent confident in the tornado sirens throughout St. Charles County.

We've received a few calls early this morning from folks in O'Fallon, MO who are hearing a tornado siren. There is no severe weather in the area and we did not issue any tornado warnings. We don't know why that siren is on. #stlwx #mowx — NWS St. Louis (@NWSStLouis) March 29, 2019

Apparently this was a malfunction. The City does not control the sirens; they are run by the County’s Emergency Management office. https://t.co/mlHiQcvBOh — City of O'Fallon (@cityofofallon) March 29, 2019