🚨 This is the moment the national emergency alert system test went off at the British Library in London. Millions of UK mobile phones blared sirens as the national emergency alert system was tested. While a library is meant to be a space of silence, that went out the window when the emergency alert rang through the British Library. Footage shows that most people were unfazed, but one person can be heard saying: "Shush!" The alerts are designed for situations where there is an imminent danger to

Here’s what to know about the nationwide emergency alert system test happening this October