An aerial view shows search and rescue personnel working on site after the partial collapse of the Champlain Towers South in Surfside, north of Miami Beach, on Thursday.

An aerial view shows search and rescue personnel working on site after the partial collapse of the Champlain Towers South in Surfside, north of Miami Beach, on Thursday. / AFP via Getty Images

At about 1:30 a.m. Thursday morning, residents of the South Florida town of Surfside awoke to a terrible sound: an entire wing of a condo building — and the lives of those within in it — crashing down.

Champlain Towers South was built in 1981 on oceanfront property near Miami. It's not at all clear what caused the building to suddenly "pancake," its 12 floors collapsing onto one another.

"That's not an old building," Surfside Mayor Charles Burkett said Thursday. "That kind of thing should not be happening."

Faydah Bushnaq, of Sterling, Va., center, is hugged by Maria Fernanda Martinez, of Boca Raton, Fla., as they stand outside the partially collapsed building on Friday. Bushnaq is vacationing and stopped to write

Faydah Bushnaq, of Sterling, Va., center, is hugged by Maria Fernanda Martinez, of Boca Raton, Fla., as they stand outside the partially collapsed building on Friday. Bushnaq is vacationing and stopped to write "Pray for their Souls" in the sand. / AP

Rescue teams search for any survivors within the sudden mountain of rubble. Family and friends wait with hope and fear for news at a reunification center nearby.

At least four people died in the disaster; 159 people remain unaccounted for. Gov. Ron DeSantis has declared a state of emergency in Miami-Dade County and President Biden has approved federal aid from FEMA.

A bed and a chest of drawers dangle from the ruins on Thursday.

A bed and a chest of drawers dangle from the ruins on Thursday. / AP

The search teams are using dogs, sonar and cameras to try to find any people trapped under the steel, concrete, and possessions from the 130 units affected.

They also used their ears.

"We are listening for sounds," said Miami-Dade Assistant Fire Chief Raide Jadallah. "It could be just steel twisting, it could be debris raining down, but not specifically sounds of tapping or sounds of a human voice."

Rain fell on the crews as they worked on Friday, and the forecast called for more.

Copyright 2021 NPR. To see more, visit https://www.npr.org.

Rescue workers walk beside the rubble as rescue efforts continued on Thursday night.

Rescue workers walk beside the rubble as rescue efforts continued on Thursday night. / AP

Rescue personnel work at the site on Thursday.

Rescue personnel work at the site on Thursday. / AFP via Getty Images

Jennifer Carr, right, sits with her daughter as they wait for news at a family reunification center near the partially collapsed building. Carr and her family were evacuated from a nearby building.

Jennifer Carr, right, sits with her daughter as they wait for news at a family reunification center near the partially collapsed building. Carr and her family were evacuated from a nearby building. / AP

People lie on cots as they wait for news at the family reunification center on Thursday.

People lie on cots as they wait for news at the family reunification center on Thursday. / AP

A man prays near where search and rescue operations continue at the site of the Champlain Towers South condo building on Friday. The man, overcome with emotion, said he had lost a relative in the collapse.

A man prays near where search and rescue operations continue at the site of the Champlain Towers South condo building on Friday. The man, overcome with emotion, said he had lost a relative in the collapse. / Getty Images

Tags: Florida