David mentioned the April 2013 Metcalf_sniper_attack.
https://en.wikipedia.org/wiki/Metcalf_sniper_attack#Sophistication_of_attack
http://www.mercurynews.com/2014/08/27/pge-substation-in-san-jose-that-suffered-a-sniper-attack-has-a-new-security-breach/
https://www.nytimes.com/2014/08/29/us/california-power-substation-attacked-in-2013-is-hit-again.html
http://sanfrancisco.cbslocal.com/2015/10/16/homeland-security-san-jose-pge-substation-attack-inside-job/
http://kron4.com/2015/10/16/video-new-development-in-south-bay-pge-substation-attack/
http://money.cnn.com/2015/10/16/technology/sniper-power-grid/index.html
Substation attack is new evidence of grid vulnerability
https://www.eenews.net/stories/1060043920Stormy weather caused most of PR to be without power.
https://www.vox.com/science-and-health/2017/9/25/16361050/puerto-rico-power-outages-deadly
http://www.cnn.com/2017/09/26/us/puerto-rico-satellite-images-power-outage-trnd/index.html
"In the wake of Hurricane Maria, Puerto Rico’s 3.4 million American citizens remain almost entirely without electrical power — but it’s not because their power plants are blown. The problem is that roughly 80 percent of transmission lines, which take power from the plants to distribution centers, are down. Nearly all the local power lines that run to residences and businesses have likely also been destroyed."
https://www.theverge.com/2017/9/25/16362410/hurricane-maria-puerto-rico-power-outages-electrical-grid-destroyed
A directed EMP attack could shut down the power grid much more extensively than any storm.
"The scenario is apocalyptic: The United States plunges into darkness after its electrical grid goes down— not just for a few hours or even a few days, but a vulnerable power system could take 18 months to recover, so long a period of time that millions would die."
http://www.sandiegouniontribune.com/business/energy-green/sd-fi-emp-threat-20170309-story.html
http://www.zerohedge.com/news/2017-04-21/total-chaos-cyber-attack-feared-multiple-cities-hit-simultaneous-power-grid-failures
https://desertshapes.blogspot.ca/search?q=EMP
http://www.differencebetween.info/difference-between-a-solar-flare-and-a-cme ,
https://www.youtube.com/watch?v=TWjtYSRlOUI
https://en.wikipedia.org/wiki/Coronal_mass_ejection ,
http://cse.ssl.berkeley.edu/coronalweather/CMEsFlares
