It would be a disaster no doubt, but people would use generators and older vehicles to temporarily fill critical functions. There might be an economic collapse, but there would also be a lot of new jobs to rebuild stuff.
Only if they remained calm and organized. When your (electricity-dependent) job is gone your first worry will be securing access to food and medicine. So depending on how much damage the incident does to power grid and how quickly governments react, you may see anything from short-term economical crisis to riots and collapse of the society.