What is an essential step after ensuring a victim of electric shock is secured from the power source?

After ensuring a victim of electric shock is secured from the power source, the most critical step is to assess the victim's condition and begin CPR if necessary. Electric shock can cause serious harm, including cardiac arrest; therefore, it's crucial to check the victim's responsiveness and breathing. If the victim is unresponsive and not breathing or only gasping, starting CPR immediately can help maintain circulation and deliver oxygen to the brain until emergency responders arrive.

Prompt initiation of CPR can significantly increase the chances of survival for someone who has experienced cardiac arrest due to electric shock. While calling emergency responders is also vital and should definitely be done if they haven't been contacted yet, the immediate action that can save a life in the moment is to begin CPR if the victim is not breathing properly.