A congressional report done several years ago estimated that 90% of the US population would be dead in a year.
"Whackers, Preppers, Whackos and Urban Myths".
No, the report did NOT say that. Here is the quotation:
"An extended blackout today could result in the death of a large fraction of the American people through the effects of societal collapse, disease, and starvation." Page 4.
http://www.firstempcommission.org/uploads/1/1/9/5/119571849/executive_report_on_assessing_the_threat_from_emp_-_final_april2018.pdf
It's true, if their assumptions are correct. I remember going into Y2K listening to an afternoon talk show about the power grid. A caller said he worked for a power station and they had ran their test and it failed. He went on to say that they restarted the station in manual mode and it was back up and running fine.