In disaster response, the critical period when trapped victims have the highest survival probability is typically the first:

Fist 72 hours are called Golden 72 Hours.
In disaster management, the first 72 hours after a disaster are considered the most critical period for rescuing trapped victims, as survival chances are highest during this window.
Most trapped victims survive only up to 72 hours without food and water.
Dehydration becomes life-threatening after 3 days (≈72 hours).