Survivors of the Florida condo collapse describe the whole building shaking and rattling before they escaped

• Champlain Towers in Surfside partially collapsed early Thursday, and 159 people are still missing.
• Residents who managed to escape have spoken about what they experienced.
• Some of the descriptions below are graphic.

Residents of a partially-collapsed condo in Surfside, Florida, have spoken out about what they heard, felt, and saw during the disaster, as search and rescue efforts continue.

As of Friday, some 159 people were still unaccounted for following the collapse of the northeast section of Champlain Towers early Thursday morning, and four people have been confirmed dead. It is still unclear how the catastrophe came about.

As of Friday, 120 people have been accounted for. Some of those who escaped the building spoke about what they went through during the collapse and its aftermath to multiple outlets.

The whole apartment rattled

Alfredo and Marian Lopez told the Miami Herald that they were asleep in their sixth-floor apartment when they heard what they thought was a thunderbolt, and felt the place rattling. Looking out of the window, all they could see was thick dust, they told the paper.

Opening the front door to the hallway, where they expected to see their neighbors' front doors, they instead looked out straight onto the beach, the paper said.

Descending via the emergency stairwell, the couple waded through a part-flooded garage to get out - with Alfredo stopping to assist a woman frozen in shock, the paper reported.

Once they got out through a gap in the wall, Alfredo "could hear people crying and screaming for help," he told the paper.

'The building had pancaked'

One resident, who was not named, told WPLG: "The whole building shook like an earthquake ... I opened my sliding glass and I saw a plume of dust, and then I opened the door and I saw that the building had pancaked in the back."

She said she had heard some screams in the aftermath.

A front door that opened onto rubble

One man, Barry Cohen, told the Associated Press that he and his wife had woken at around 1:30 a.m. to what they believed was a thunderstorm.

Opening the door to their hallway, what they found was "a gaping hole of rubble," Cohen said.

The couple's route to escape was perilous.

Trying to exit via the stairs down to the pool area, they found that the door wouldn't open, and when they went down to the basement there was rising water, the AP reported.

They were finally rescued, screaming for help, by a cherry picker that firefighters were using, according to the AP.

An arm sticking out of the wreckage

One resident, a young boy, was rescued only after a passerby happened to see his arm sticking out of the rubble, CNN reported.

Nicholas Balboa told the network that he had been walking his dog as the collapse happened, and went to the back of the building, where he heard a boy's voice screaming.

"Then I saw an arm sticking out of the wreckage, and he was screaming, you know, 'Can you see me?'" he told CNN.

Though Balboa and another person were unable to pull the boy out by themselves, Balboa signaled to police nearby, who brought rescuers to the scene and extricated him.

'Nothing but dust'

One survivor woke up on the second floor of the building to "a large crumbling noise," he told WPLG. The channel did not name him.

"All we could see was white dust, thick, we saw nothing but dust," he said. "And we couldn't breathe, and it was really bad."

He, his mother and his sister all survived the collapse, WPLG reported.

Search-and-rescue efforts at the building's site are to continue. Officials said on Friday they were hopeful that more survivors will be found.