Thermal drones seek survivors after deadly Italy glacier collapse-know what are thermal drones

Rescuers used thermal drones Monday to search for possible survivors trapped under ice after an avalanche set off by the collapse of the largest glacier in the Italian Alps killed at least six people and injured eight others.

Authorities said they did not know how many climbers were hit when the glacier gave way Sunday on Marmolada, the highest mountain in the Italian Dolomites.

"We found bodies torn apart, in a shapeless tide of ice and debris stretching over 1,000 metres (3,280 feet)," Gino Comelli from the Alpine Rescue Service told the Corriere della Sera daily Monday.

The disaster struck one day after a record-high temperature of 10 degrees Celsius (50 degrees Fahrenheit) was recorded at the glacier's summit.

Emergency services spokeswoman Michela Canova told AFP an "avalanche of snow, ice and rock" hit an access path at a time when there were several roped parties, "some of whom were swept away".

The total number of climbers involved was "not yet known", she said.

Helicopters and sniffer dogs were called off as night fell and amid fears the glacier may still be unstable.

But rescuers used drones equipped with thermal cameras to continue the search overnight and early Monday, Canazei mayor Giovanni Bernard told AFP.

"It is difficult for the rescuers in a dangerous situation", he said.

What are thermal drones?

Thermal imaging drones work on the basis of temperature. They have instruments that tell users about the temperature variations in a specific place. Where they come in handy is during emergency situations. For instance during the Italian glacier tragedy, the thermal drones are being used during the night to locate survivors. Their bodies' temperature will be higher than the ice and the instruments on the thermal drone will be able to locate the area they are in, helping rescue them faster. These thermal drones also save rescuers from needlessly endangering their lives when the situation is precarious, especially during night. In fact, thermal drones can be used even during earthquakes and fires to locate survivors.

Images of the avalanche filmed from a refuge close by show snow and rock hurtling down the mountain's slopes.

"It's a miracle we're alive," Stefano Dal Moro, an engineer who was hiking with his Israeli partner told Corriere della Sera.

"There was a dull noise, then that sea of ice came down. It's useless to run, you can only pray that it doesn't come your way.

"We crouched down and hugged each other tightly as the ice passed".

Bodies dug out of the ice and rock were taken to the village of Canazei.

Italian Prime Minister Mario Draghi was expected to visit Canazei later Monday.

Massimo Frezzotti, a science professor at Roma Tre University, told AFP the collapse was caused by unusually warm weather linked to global warming, with precipitation down 40 to 50 percent during a dry winter.

"The current conditions of the glacier correspond to mid-August, not early July," he said.

The Trento public prosecutor's office has opened an investigation to determine the causes of the tragedy.