Residents of some parts of Southern California were shocked when their television programming was suddenly interrupted by a warning about the apocalypse. The Orange County Register reports that a man’s voice came over the air proclaiming: “Realize this, extremely violent times will come.”

The disruption predicting the end of the world lasted for about one minute on Thursday, the paper reports. Customers of the Cox and Spectrum cable systems were among those experiencing the disruption.

“The problem occurred because of one or more radio stations conducting an emergency test, Joe Camero, a spokesman for Cox, said Thursday,” The Register reports. “Cable systems pick up such alerts, and viewers should have seen just a typical emergency-broadcast test.”

The report quotes Camero saying: “With these tests, an emergency tone is sent out to initiate the test. After the tone is transmitted, another tone is sent to end the message. It appears that the radio station (or stations) did not transmit the end tone to complete the test.”

The broadcast then apparently picked up some audio that bled into the alert. “Camero said Cox technicians shut down the emergency test as soon as they became aware of the problem,” the report notes.

Cox and Spectrum were reportedly investigating who sent out the alert and attempting to determine whether it was done accidentally or on purpose.

The report quotes Dennis Johnson, a spokesman for Spectrum, saying: “We have confirmed that we were fed an incorrect audio file.”