iPhone 7 Blanked Out?

Last night, I set my iPhone 7 to charging and started the 10.0.2 update. When I checked a few minutes later, the screen had gone completely BLANK. I tried force quitting, but the sensor in the home button wasn't working, so I couldn't force quit. It seems that after the update, the phone went blank and wasn't turning on. I will go to the genius bar tomorrow, but any suggestions?