Five days without water. Forty without food. That is how far the human body can go when trapped under tons of concrete.
A University of Washington study reviewed 30 years of rescues and found survivors who endured more than 48 hours under the rubble, some for up to 13 or 14 days. In extreme cases, such as those recorded after earthquakes, successful rescues have been carried out up to 36 days after the collapse.
Experts agree on something that sounds contradictory: do not keep shouting nonstop. Conserving oxygen is key.
The recommendation is to stop moving, protect your nose and mouth from dust, check for bleeding, and wait for the right moment to call for help: three knocks against a wall or pipe, or a whistle, and then remain silent to listen for rescuers.
A doctor who worked during the Haiti earthquake in 2010 sums it up this way: the determination to survive also matters.