Tornado sirens ‘accidentally' activated in multiple Chicago suburbs—again

The video in this report is from a story Aug. 18, when the sirens were initially “accidentally” activated.

Tornado sirens were “accidentally” activated Friday morning across multiple Chicago suburbs–again.

Reports of sirens going off in DuPage County began hitting social media just before 10 a.m. Some police departments and villages acknowledged the sirens went off despite no severe weather.

“The severe weather warning sent at approximately 9:55 a.m. today through DU-COMM was issued in error and was a false alarm,” the Village of Oak Brook said in a Facebook post at 10:05 a.m. The village went on to say that residents should remain “weather-aware,” as the entire Chicago are is under a “slight” risk of severe weather Friday afternoon and evening, which ranks as level two.

“We apologize for any confusion caused by the earlier notification and appreciate your understanding,” the village said.

An NBC producer who was in Glen Ellyn at the time heard the sirens going off, with the alert lasting about 30 seconds.

At 10:10 a.m., DuPage Safety Communications (DU-COMM), which manages the alert system, released an update saying it was aware a tornado siren was activated, but that it was not part of severe weather or a scheduled test.

“There is no severe weather, and this was not part of a planned test,” the update said. “We are investigating the cause and apologize for the confusion.”

The incident comes two days after tornado sirens were “accidentally activated” by a DU-COMM employee in the middle of the night in all of DuPage County during a planned test.

“These tests are designed to assess the functionality of the technology without activating the sirens,” DU-COMM said at the time.

In May of 2025, DuPage County launched a based on NWS warnings that are meant to activate without human intervention. At the time, officials said the system was a “significant advancement in public safety technology.”

The system, officials said at the time, is meant to activate in precise areas automatically if an outdoor warning if any local zones fall within an overlap of a weather warning.

NBC Chicago reached out to DU-COMM for comment on this story but did not immediately hear back.

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