I experienced it first hand in Madrid. This was much scarier than I would have imagined.
News travelled extremely slow: phone coverage was just barely enough to receive a couple text messages every 15 minutes or so. News spread on the street, I even saw a group of 20 people hunched around someone owning a hand-held radio in the streets.
Just before power was restored, things started to get worse, as the phone coverage went completely out (presumably batteries were depleted). People were in between enjoying the work-free day, and starting to worry about how tomorrow would look like if power didn't come back.
I received a free PCB from AirGradient a few years back, and am very happy with it. The only thing I was surprised by, was that by default the Arduino code asks for WiFi connection and then sends the collected data back to AirGradient.
News travelled extremely slow: phone coverage was just barely enough to receive a couple text messages every 15 minutes or so. News spread on the street, I even saw a group of 20 people hunched around someone owning a hand-held radio in the streets.
Just before power was restored, things started to get worse, as the phone coverage went completely out (presumably batteries were depleted). People were in between enjoying the work-free day, and starting to worry about how tomorrow would look like if power didn't come back.