CNN  — 

Sounds offer hope, officials said Friday amid a frantic, fast-paced mission to find survivors trapped beneath the rubble of a partially collapsed condominium tower in Surfside, Florida.

Though it’s unclear how many people were in the portion of the 12-story building that fell, scores of victims remain unaccounted for. The death toll has risen to four.

Rescuers above and below the rubble are using light and heavy machinery, along with an array of technology, in their search, said Raide Jadallah, assistant chief of operations for the Miami-Dade Fire Rescue Department

As machines move the debris – ever so carefully so as not to disturb voids where survivors might be trapped – rescue workers are employing listening devices, sensitive enough to hear a watch ticking, to detect sounds indicating someone might be trying to make their location known, officials said. It’s a tricky science because there are so many noises emanating from the debris, Jadallah said.

“It’s not specifically human sounds. It could be tapping. It could be steel kind of twisting. It could be some of the debris kind of raining down,” he said. “From below, we continue using light machinery – saws, jackhammers – as we continue to tunnel through underneath.”

He added: “We have hope. Every time we hear a sound, we concentrate in that area, so we send additional teams, utilizing the devices, utilizing canine.”

Efforts just beginning

People can survive a week or more beneath rubble, so despite being a day-and-a-half into the rescue efforts, the mission is still at an early stage, officials said.

On a scene so fraught with peril – conditions are exacerbated by wind and rain, which can disturb the rubble – those working in the debris are risking their own lives, Jadallah pointed out. Fires erupting from overheated lithium-ion batteries and other combustible material also pose dangers, officials said.

Miami-Dade County Mayor Daniella Levine Cava echoed Jadallah’s concerns.

“This work is being done at extreme risk to these individuals,” the mayor said. “Debris is falling on them as they do their work. We have structural engineers on site to assure that they will not be injured, but they are proceeding because they are so motivated.”

At least 130 firefighters were part of the effort as of Friday morning, Jadallah said. That’s in addition to other local, state and federal personnel descending on the scene over the course of the day.

boy rescued from rubble surfside
Video shows boy rescued from rubble in building collapse
01:19 - Source: CNN

The state fire marshal’s office is sending additional urban search-and-rescue teams, and other teams are on stand by, said Kevin Guthrie, director of the Florida Division of Emergency Management. The regional coordinator for the Federal Emergency Management Agency, which has issued an emergency declaration, arrived overnight. About 15 more FEMA officials, along with additional state emergency management staff, will arrive sometime Friday, Guthrie said. And more assistance was en route from Orlando and Naples early Friday, officials said.

As search dogs sniff through the rubble and rescuers use technology like sonar and cameras to explore voids that might provide refuge, the fires popping up remain a worry – and not solely because fire itself poses danger.

The fires, in some cases, are disturbing the infrared technology that rescuers employ to find survivors, and the water used to douse the blazes “adds a tremendous amount of weight” to the rubble,” said state Fire Marshal Jimmy Patronis. As crews pump the water out, they’re “also shifting materials that creates a ripple effect,” he said.

“It then challenges the integrity of what’s still standing there – and then that delicate balance of saving lives while risking lives,” he said.

The work is “methodical, fast-paced, while at the same time, deliberate,” said Chief Scott Goldstein, an urban search-and-rescue specialist who heads the Montgomery County Fire & Rescue Service in Maryland.

It remains a rescue op

The priority is finding those beneath the rubble, Goldstein said, and rescuers are working to maintain their focus so as not to “miss any signs and indications of a victim being trapped in the building.” They’re also working to stay hydrated, as temperatures are in the mid-80s and humidity is soaring.

The condo tower appears to have suffered what’s known as a “pancake collapse,” meaning the walls that provide the building’s structure failed, so voids may be less common here than in a building where only one wall or a cantilever or other supporting mechanisms failed, he said. However, a video put out by county officials Thursday night shows voids in the underground parking area, he noted.

“Each of those spaces provide opportunities for a survivable area. Seven to 10 days, it’s not uncommon for someone to be found alive and removed from a horrific event like this,” Goldstein said.

While rescuers pore through the rubble – requiring them at times to get on their hands and knees and, in the tightest areas, on their stomachs – the building is shifting, so the remaining structure is constantly being monitored, he said. As teams move the rubble, the debris pile is assessed and wood and heavy timber are put into place for stabilization. The weight of the rain isn’t helping, Goldstein said.