Between hope and heartbreak: How rescuers hunt for life under mounds of concrete

NEW DELHI: When disaster strikes, be it a building collapse or an earthquake, the enormous pile of concrete and steel is the first hurdle between life and death. For rescue teams, extricating victims from the mounds of debris is a race against time.

At a rescue site, operations shift systematically from initial scene stability assessments and surface rescues to deeper cavity searches. Rescuers use an array of high-tech gear, such as life detectors, boremeters, specialised cameras and magnetic microphones along with sledgehammers. The trained K-9 squads are indispensable, as always.

TOI spoke with officials of disaster response agencies such as National Disaster Response Force (NDRF). They explained the finer points of a high-stakes operation where nothing is left to chance.

There has been some criticism regarding the pace of rescue at the Saidulajab building collapse site. An official who was present there said that every move is a calculated, strategic decision. “It may seem slow-paced at first glance but we follow a highly structured, multi-phase blueprint to locate the victims.”

“The operation begins with reconnaissance to evaluate the stability of the scene, followed by the rescue of survivors who are easily visible or audible,” a senior NDRF officer said.

After that, the responders focus on a complex “cavity search” mission. They look for signs of life under collapsed beams or stairs. Cutting and drilling through these “sensitive spots” is challenging.

The rescue does not focus on one job at any one moment. Different tasks proceed in sync. For example, while the cavity search is on, other rescuers remove the debris from pockets that are marked “clear” by a supervisory officer. Heavy machinery such as cranes are used to break down larger pieces of a structure and remove them. “Before lifting any concrete slab, we use special cameras and equipment to inspect underneath and confirm that there are no survivors there,” said an NDRF commandant.

Behind the scenes, police, fire officials, ambulance services and hospitals are kept in the loop about the missing persons. It is only after the last missing person is accounted for that the final phase of general debris clearance starts.

“Interestingly, basic manual implements like sledgehammers, pry bars and steel pipes are our primary tools for surface or small debris removal as the rescuer remains in control of the environment while using them,” said a rescuer involved in the operation at Saidulajab.

For breaching obstacles, the team deploys an angle cutter to slice through concrete and metal. A portable air plasma cutting machine with a lightweight, non-breakable air cutting torch is also used.

For deeper structural exploration, the responders use core drills and concrete cutters to pierce through thick slabs, creating channels to insert equipment like the life detector, which is a magnetic microphone that catches acoustic disturbances. “The life detector senses survivors by identifying distinctive electromagnetic signals generated by a human heartbeat,” an NDRF officer said.

The rescuers also use a borescope, equipped with a camera, that allows them to "peer deep into the wreckage. This device can be inserted into the debris through small holes so that the teams can see the interior on a monitor,” the officer added.

The teams rely on lifting tools that are capable of handling loads ranging from 1 tonne to 70 tonnes, as well as versatile airlifting bags to lift the concrete. These bags are effective on uneven ground where standard jacks are unstable.

The moment a device captures a sign of life, a mild groan or a faint tap, two-way communication devices are lowered into that space.

Of course, there are the dogs. The K-9 squad is a trained and vital asset. The dogs’ acute sense of smell proves that even in a high-tech battle against time, a trained canine is irreplaceable.

At Saidulajab, the rescue personnel used four dogs on Saturday and Sunday.