As Pornsak Seingsing ran for his life out of a collapsing high-rise building in Bangkok, he could hear terrified cries at his back.
"I looked behind and I heard Burmese people screaming," he told the ABC.
"I heard someone calling 'mother, mother, mummy' — I don't think that person made it."
The 29-year-old is one of dozens of friends and family who have waited silently and nervously as emergency workers comb through tonnes of concrete, steel and glass, looking for survivors.
The punishing heat and humidity of the Thai capital abates only a little at night, yet the rescue operation has not stopped since the earthquake hit around lunchtime on Friday.
The more than 30-storey building was under construction and when the tremor hit it pancaked on top of itself, creating a cloud of dust and debris that engulfed the surrounding streets while trapping dozens of workers beneath.
"I was so terrified, it was so scary," Pornsak said.
"The building started to bend, and there was a sound like an explosion from the top, and heavy blocks of cement were falling down, people were screaming.
"I was on the fifth floor, I think I was the last one that made it out."
Pornsak was working as a welder on the building, which was destined to become a new office for Thailand's state auditors, and on Saturday he was waiting for news of two friends — one Burmese and one Thai.
He thinks about 80 per cent of the people working on the site were migrants, mostly from neighbouring Myanmar, which has been in the midst of a devastating and bloody civil war since 2021, and has now borne the brunt of the earthquake's devastation.
One group of Burmese workers say they have 16 close friends and family members who are missing and believed trapped under the rubble.
Another young Cambodian woman, who only wanted to be referred to by her first name Nul, was anxiously awaiting news of her 23-year-old brother, who she thinks was working on the 26th floor.
"I feel miserable, and my mum keeps crying," the 21-year-old said, her own emotions brimming just below the surface.
"She's at home now, and she's crying all the time."
The family have been in Thailand for more than six years, having migrated in the hope of earning a better income than they could in Cambodia.
"I really wish my brother could come back. Please, please be safe and come back."
Scale of disaster still being revealed
In Bangkok, local authorities say around 10 people have died, at least 30 are injured and about 80 are still missing.
The full scale of the disaster in Myanmar is still being revealed, but the death toll announced by Burmese state media keeps rising sharply, passing 1,600 late on Saturday night, with more than 3,400 injured.
The 7.7 magnitude earthquake's epicentre was near Myanmar's second largest city Mandalay, at a shallow depth of only 10 kilometres.
There are grave fears about Myanmar's ability to cope with the aftermath of this disaster.
Aid groups say it could not have hit at a worse time with more than 3 million people internally displaced due to the brutal civil war.
The leader of the military junta has made a rare plea for international assistance, asking for help from any country willing to provide it.
Analysis by the US Geological Survey estimates the overall death toll could be well into the tens of thousands.
X-ray, drones, dogs used to search for survivors
In Bangkok, damage is isolated to certain parts of town.
Only a couple hundred metres from the collapsed building is the Chatuchak Market — popular among tourists and locals — which continued to operate on the weekend.
But in that area around Kamphaeng Phet 2 Road, hundreds of rescuers, paramedics, volunteers and other support workers fill the street, which has been closed to all traffic except emergency vehicles and trucks bringing in excavators and other machinery needed to search for survivors.
Search dogs have been through the site, drones and robots are being used as part of the rescue efforts, and the Bangkok governor Chadchart Sittipunt announced that X-ray machinery from Israel was due to arrive overnight to help find any more survivors in the debris.
He also said fresh air was being circulated through the building in the hope it might sustain anyone left alive.
Specialist rescue worker Pakapon Suka told the ABC he had been working there for more than 24 hours without sleep, and had recovered two people from the ruins, only one of whom survived.
"The man who survived, his head was pointing downward and into a hole, that's how he survived," he said.
"He was talking and could answer me, we'd talked for almost an hour before he stopped.
"But I couldn't understand him well because he was Burmese, he was only about 25 years old."
Pakapon has been a rescuer for 37 years, and worked on the tsunami recovery 20 years ago as well as another major building collapse in Korat, a town in the north-east of Thailand.
He thinks this operation could go on for a month.
"From the outside it looks like a pile of concrete, but inside there is lots of dust, steel, and broken mirrors".
'Unstable structure' report from fire authorities
The lack of serious damage elsewhere across the Thai capital has prompted questions about why this building collapsed so easily.
It was set to be the new building of the State Audit Office, which has now announced an independent investigation and invited engineers to assess any structural failures.
The building had been under construction since 2020, at a cost of more than 2.13 billion Thai baht ($100 million AUD).
The Nation Thailand reports that the Bangkok Fire and Rescue Department cited an 'unstable structure' as contributing to the collapse.
Pornsak, the welder, thinks a building site of that size should have had many more workers and expressed concerns about the quality of the construction.
It is now a race against time to find any more survivors beneath the pile of rubble, with authorities estimating dozens are still trapped.
"I hope those people made it to the basement," said Pornsak.
"That will be the only chance they have to survive, and I hope that they will be found."
As the hours creep by, families wait patiently, occasionally overwhelmed by emotion and breaking into sobs.
All around them the media beams images of the warped, mangled remains to the world.
Late on Saturday, people rushed to the edge of the construction site, as news spread that someone might have been found.
A woman watching on as paramedics readied a stretcher turned away into the shoulder of a loved one in floods of tears, anticipating who might be rescued.
But after at least 20 minutes of waiting her hopes went unanswered, and eventually she returned to the crowd quietly watching and waiting to find out the fate of their loved ones.
