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Did you survive FEMA’s Emergency Alert System test? The Federal Emergency Management Agency (FEMA) sent alerts to all cell phones, televisions and radios on Wednesday, Oct. 4.

People who muted their phones still received “a special sound.” Those who turned off their phones did not receive a signal.

FEMA conducted the test to check for the system’s effectiveness. But conspiracy theories ran amok on social media.

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Some people said the alert will “activate” dormant diseases within vaccinated people. They warned iPhone users to turn off their phones.

Others said the alert would activate nanoparticles that were injected into people’s bodies during the pandemic.

A FEMA spokesperson said in an email to USA TODAY there are no known harmful health effects from the signal. It’s just a very annoying sound.