eli5 How do military units navigate chaos and maintain direction when faced with casualties, especially if the commanding officer is killed, as depicted in the opening scene of “Saving Private Ryan”?

Question

Recently I watched “Saving Private Ryan” again, and it made me have some questions. For example, in the opening scene of soldiers rushing to the beach, most of the soldiers were almost dead before they even got out of the landing craft. If the commander was also killed, what about the remaining soldiers? Who should direct the people? How should each unit perform the tasks assigned before departure?

In: Other

Answer 1

Chain of Command: The entire military is composed of ranks, from O-10 down to E-1. You would know each others exact ranking in the organization, down to the day if needed.

Contingency Plans: The military spends the majority of it’s time planning and training for every conceivable possibility in war. If it can happen, there’s a binder somewhere with orders on how to navigate through it probably.