How long can they survive trapped in the ruins after the earthquake?

How long can trapped people survive in the ruins of an earthquake? Up to a week or more, experts say, but that depends on their injuries, how they were captured and weather conditions.

Search teams from around the world have joined local emergency personnel in Turkey and Syria to search for victims of the devastating earthquake that claimed thousands of lives.

Most rescues happen in the first 24 hours after a disaster. After that, the chances of survival decrease with each passing day, experts say. Many victims were badly injured or buried by rocks or other debris.

Access to water and air are key factors for survival, along with weather conditions. Poor winter conditions in Syria and Turkey have hampered rescue efforts, with temperatures dropping well below freezing.

"Typically, it's rare to find survivors after five to seven days, and most search and rescue teams will consider suspending operations until then," said Dr. Jeron Lee, an emergency and disaster medicine specialist at Massachusetts General Hospital.

"But there are many stories of people surviving well beyond seven days. Unfortunately, these are usually rare and exceptional cases."

People with traumatic injuries, including crush injuries and limb amputations, face the most critical period of survival, said Dr. George Champas, an emergency medicine specialist at Northwestern University.

"If you don't get them out in one hour, in that golden hour, there's really very little chance of survival," he said.

Those with other illnesses, whose health depends on medication, also face poor odds, Champas said.

Age, physical and mental condition are important factors.

"There were also a lot of miraculous rescues, people surviving in terrible conditions," said Dr. Christopher Colwell, an emergency medicine specialist at the University of California, San Francisco. "They're usually younger people and they've been lucky enough to find either a pocket in the rubble or some way to access air and water."

After the 2011 earthquake and tsunami in Japan, a teenager and his 80-year-old grandmother were found alive after nine days trapped in their flattened home.

A year earlier, a 16-year-old Haitian girl was rescued from the ruins of the earthquake in Port-au-Prince after 15 days.

Mental state can also affect survival. People trapped next to the bodies of the victims, who have no contact with other survivors or rescuers, may lose hope, says Champas.

"If you have someone alive, you rely on each other to keep fighting."