NEW YORK — How long can people survive in the rubble of an earthquake?

A week or more under the best circumstances, some experts say. That means the trapped victims aren’t seriously injured, they have air to breathe and the weather isn’t too hot or too cold.

In Italy, more than 200 people have been rescued since a strong earthquake hit Wednesday, and rescue efforts are continuing. The quake struck in the middle of the night as people were sleeping, raising the possibility that more people were trapped in buildings.

HOPE FADES WITH TIME

The vast majority of rescues occur in the first 24 hours after a disaster. After that, the chances of survival drop as each day passes, experts say. Most victims are badly injured or buried by falling stones or other debris.

“The more serious the injury, the less the chance of survival,” said Dr. Paul Auerbach, a professor of emergency medicine at Stanford University who has been part of rescue teams after earthquakes in Haiti and Nepal.

CONTRIBUTING FACTORS

Survival mainly depends on water, temperature and air to breathe.

“Food is not so much of an issue” — people can survive for weeks without it, said Dr. Richard Moon, a Duke University expert on survival.

But most can only last a few days without water, he added.

The temperature is also a factor: If it’s very hot, a person can sweat and begin to overheat. “You’re losing more water” and may not make it a few days, Auerbach said.

And having enough air to breathe under the rubble is also key.

SURVIVAL STORIES

Many devastating earthquakes have been accompanied by “miracle” stories of people rescued days after many had given up hope.

In 2011, a Japanese teenager and his 80-year-old grandmother were found alive after nine days trapped in their flattened home after the earthquake and tsunami that devastated Fukushima. The year before, a 16-year-old Haitian girl trapped for 15 days was rescued from the earthquake rubble in Port-Au-Prince.

“When people are pulled out 10 days afterward, people go ‘it’s a miracle.’ And from an emotional perspective, it is a miracle. But it’s also physiologically possible,” Auerbach said.

That said, “it’s the exception, not the rule,” he added.