I have one locally sourced answer to that question: our emergency sirens failed their monthly test run because their internal clocks were out of sync! Source (

I have one locally sourced answer to that question: our emergency sirens failed their monthly test run because their internal clocks were out of sync! Source (in Dutch): https://www.nu.nl/binnenland/5164385/ https://www.nu.nl/binnenland/5164385/