What would the residents of a big city lose in the event of an electrical failure?

In the event of an electrical failure, the life of a big city freezes, since there is no light, no heat, all electromechanical devices do not work, there is no power supply for computers, and so on.

Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.