the crew is not lost.
they are ashore.
Most of the crew are essential for battle-ready underway operations. Some are not - depends on their department and rating.
Getting underway with a "skeleton crew" was Navy SOP in my day. That was the purpose of "duty days". Still, that doesn't mean the ship is battle ready with such a small percentage of the crew. It's purpose was to get the ship out of an enclosed harbor (kill zone) into open sea to fight another day. A lesson learned with our carriers at sea during Pearl.
Am I wrong regarding today's Navy?