For people trapped beneath collapsed buildings after an earthquake, survival depends on several factors, including the severity of their injuries, weather conditions, and access to air and water.
Experts say victims whose injuries are not life-threatening can survive for a week or longer, provided temperatures are not excessively hot or cold, reports ABC News.
In Venezuela, rescue teams have been working around the clock to locate survivors after two powerful earthquakes struck the northern state of La Guaira last Wednesday.
The earthquakes caused the total or partial collapse of more than 770 buildings, while continuing aftershocks have complicated rescue operations.
Specialists say most successful rescues take place within the first 24 hours after a disaster.
Beyond that period, the likelihood of survival declines with each passing day, as many victims suffer serious injuries or become trapped beneath heavy stones and other debris.
People buried under rubble have a better chance of survival if they remain inside a debris-free pocket that protects them from severe injury while awaiting rescue, such as beneath a sturdy desk, said geophysicist Victor Tsai from Brown University.
Experts refer to such protected areas as survivable void spaces.
Emergency response expert Joseph Barbera, an associate professor at George Washington University, said a person’s chances of survival may decrease if the building collapse releases fire, smoke or hazardous chemicals.
As time passes, access to breathable air and drinking water becomes increasingly critical.
“You could survive a while without food,” Barbera said. “You could survive less without water.”
The temperature inside the collapsed structure can also influence survival, while weather conditions above ground may affect the speed and safety of rescue efforts.
According to the Venezuelan government, more than 2,600 rescue personnel from around the world have arrived with trained search dogs and specialised equipment.
Rescue operations in La Guaira, the worst-affected area, appeared considerably more organised on Sunday after residents had voiced frustration and anger over what they described as an inadequate response in the days following the earthquakes.
Barbera said it is often vital for trapped survivors to receive emergency medical treatment before rescuers remove them from the rubble.
Without immediate care, toxins released from crushed muscles can enter the bloodstream and send survivors into shock after they are rescued.
History has shown that survival is possible even after many days beneath the rubble.
Following the 2011 earthquake and tsunami in Japan, rescuers found a teenager and his 80-year-old grandmother alive after they had spent nine days trapped inside their collapsed home.
A year earlier, rescuers pulled a 16-year-old Haitian girl from the rubble in Port-au-Prince after she had survived for 15 days.
Experts say the safest response during an earthquake varies depending on where people are, as building standards differ around the world.
Regions located along active fault lines often enforce earthquake-resistant building codes, although such protections are not universal.
In many countries, including the United States, authorities recommend people drop, seek cover and hold on unless they are already close to a building exit.
Taking shelter beneath a heavy table or beside sturdy furniture can create a survivable void if the roof collapses.
They also advise covering the face with a cloth or mask to reduce exposure to dust and debris.
People trapped beneath rubble should avoid unnecessary movement and conserve their energy.
They should ration any available food and water, listen for rescuers calling out, and use nearby objects to make noise and attract attention.
If they have a mobile phone, they should preserve its battery and attempt to call for help in short intervals each day.
