Earthquakes can result in collapsed structures with the potential to entrap individuals. In some cases, people can survive entrapment for lengthy periods. The search for and rescue of entrapped people is resource intensive and competes with other postdisaster priorities. The decision to end search and rescue activities is often difficult and in some cases protracted. Medical providers participating in response may be consulted about the probability of continued survival in undiscovered trapped individuals. Historically, many espouse a rigid time frame for viability of entrapped living people (eg, 2 days, 4 days, 14 days). The available medical and engineering data and media reports demonstrate a wide variety in survival “time to rescue,” arguing against the acceptance of a single time interval applicable to all incidents. This article presents historical evidence and reports from the 2010 Haiti earthquake. Factors that may contribute to survival after entombment are listed. Finally, a decision process for projecting viability that considers the critical factors in each incident rather than adhering to a single time frame for ceasing search and rescue activities is proposed. (Disaster Med Public Health Preparedness. 2011;5:13–22)