The incident is known as the Carrington Event, and it cause enormous interference even if people used small-scale electronic equipment.
This kind of event must have happened many times in the past, too, with humans surviving. However, only recently we have started to be completely dependent on electronic equipment.
The truth is we would suffer a lot if we underestimate the dangers of a possible Carrington, or even more powerful events.
Even if this wouldn’t exactly wipe out humanity in a split second, it would still represent an enormous challenge.
There wouldn’t be any electricity, heating, air conditioning, GPS, or internet – and most of the food and medicines would go bad.