FDNY veteran who responded to both World Trade Center terror attacks weighs in on Miami collapse rescue effort

The fact that rescuers heard banging sounds from beneath the collapsed Champlain Towers South apartment building in Surfside, Fla., just outside Miami, is a good sign that they may yet find additional survivors, according to a former FDNY member who responded to both terror attacks on the World Trade Center in New York City.

To find them, rescuers deploy sonar equipment in a perimeter around the fallen structure, he said. The devices communicate with one another to help locate possible survivors and send audio to a human operating the equipment. And if there are no other explanations for the banging sounds, then they are good signs that survivors are trapped in those voids and trying to attract the attention of rescuers, who use sonar equipment to try and locate victims within the rubble, he said.