You're right, on September 11, 2001, all types of problems were caused due to Power outages. In addition, the blackout on August 14, 2003 knocked out power throughout parts of the Northeastern and Midwestern United States.
Now, they will tell you that they believe there was Russian interference on the 2016 election caused by computer hacks. What would make you think they would not try that on US power grids and communication systems? In addition, you don't think China and North Korea wouldn't assist them?