Heart-stopping footage has caught the terrifying moment a window cleaner in Thailand clung onto a swaying high-rise building after the country was struck by its strongest earthquake in nearly 200 years, on Friday. 

The hapless worker had just his safety harness, helmet and rope to protect him as a huge 7.7 magnitude earthquake struck Myanmar and nearby Thailand, which has so far claimed the lives of more than 1,000 people.

Seconds after the earthquake began, the cleaner can be seen putting his head down and clinging onto the edge of the building, as tons of water from a rooftop swimming pool poured over the sides.

The worker stayed as still as he could before using the rope to try and descend the building.

However, as he began to move he appeared to swing to the side amid the movement to the building caused by the powerful quake.

By all accounts, the window cleaner’s lucky escape was nothing short of miraculous, given the number of collapsed buildings and rising number of fatalities recorded so far following the disaster. 

As of Saturday, 1,002 people have died and another 2,376 injured, with 30 others missing, Myanmar’s military-led government said in a statement.

In Mandalay, the country’s second-largest city, rescue workers have been working around the clock pulling bodies from the rubble of collapsed buildings, while also searching for any survivors.

Over in  neighboring Thailand, the quake rocked the greater Bangkok area, home to some 17 million people – many of whom live in high-rise buildings – and other parts of the country.

Bangkok city authorities said so far that six people have been found dead, 26 injured and 47 are still missing, most from a construction site near the capital’s popular Chatuchak market.

When the quake hit, the 33-story high-rise being built by a Chinese firm for the Thai government wobbled, then came crashing to the ground in a massive plume of dust that sent people screaming and fleeing from the scene.

On Saturday, more heavy equipment was brought in to move tons of rubble, but hope was fading among friends and family members of the missing that they would be found alive.

‘I was praying that that they had survived, but when I got here and saw the ruin – where could they be? In which corner? Are they still alive? I am still praying that all six are alive,’ said 45-year-old Naruemol Thonglek, sobbing as she awaited news about her partner, who is from Myanmar, and five friends who worked at the site.

‘I cannot accept this. When I see this I can’t accept this. A close friend of mine is in there, too,’ she said.

Earthquakes are rare in Bangkok, but relatively common in Myanmar. The country sits on the Sagaing Fault, a major north-south fault that separates the India plate and the Sunda plate.

Brian Baptie, a seismologist with the British Geological Survey, said it appears a 125 miles (200km) section of the fault ruptured for just over a minute, with a slip of up to 16.4 feet (5 metres) in places, causing intense ground shaking in an area where most of the population lives in buildings constructed of timber and unreinforced brick masonry.

‘When you have a large earthquake in an area where there are over a million people, many of them living in vulnerable buildings, the consequences can often be disastrous,’ he said in a statement.

‘From initial reports, that seems likely to be the case here.’

Friday’s quake has been named as the strongest to hit neighbouring Thailand since the 1839 Ava Earthquake, which the Myanmar Institute of Earth and Planetary Sciences estimates measured up to 8.3 in magnitude.

Thailand was impacted by the Boxing Day tsunami in 2004, which was caused by the third most powerful earthquake ever recorded, with an estimated magnitude of 9.25. 

The gigantic undersea tremor struck off the coast of Indonesia and unleashed a series of catastrophic tsunamis across a dozen countries, which obliterated everything in their path and killed an estimated 230,000 people.

Chelsea King, a British expat living in Bangkok, told MailOnline that she was ushered away from her building by security guards as the initial quake struck.

She said she could see ‘towering skyscrapers…visibly swaying’.

‘Many of these buildings are condos or hotels with rooftop pools, and water was cascading down like waterfalls due to the force of the tremors.

‘The street was chaotic, with people running out of buildings, carrying pets and children, shouting in panic.

‘I was in shock, unable to process what I was seeing – it felt like something out of a disaster film.’

When they were finally allowed back in, she was able to rescue her cat, Mo, and pack a small bag of necessities before escaping down eight flights of stairs.

Chelsea was fortunate that her building ‘appears undamaged’. But she says friends are unable to return to their homes due to structural damage.

‘My partner, who teaches on the city’s outskirts, is also struggling to get back home, with the BTS and MRT [metro system] shut down and the roads at a standstill.’ 

Kelly Rhodes, a tourist staying at the Okura Prestige in Bangkok, told MailOnline they were evacuated down 24 flights of stairs when the quake struck.

As airlines began to halt some flights, she said: ‘We are now trying to organise flights out but it’s chaos.’

‘We can’t get out of the city. Traffic is at a standstill total gridlock.’

The earthquake was forceful enough to send water sloshing out of pools, some high above the street in high-rises, as the tremor shook.

Witnesses in Bangkok said people ran out onto the streets in panic, many of them hotel guests in bathrobes and swimming costumes as water cascaded down from an elevated pool at a luxury hotel. 

‘All of a sudden the whole building began to move, immediately there was screaming and a lot of panic,’ said Fraser Morton, a tourist from Scotland, who was in one of Bangkok’s many malls shopping for camera equipment.

‘I just started walking calmly at first but then the building started really moving, yeah, a lot of screaming, a lot of panic, people running the wrong way down the escalators, lots of banging and crashing inside the mall.’

Like thousands of others in downtown Bangkok, Morton sought refuge in Benjasiri Park – away from the tall buildings all around.

‘I got outside and then looked up at the building and the whole building was moving, dust and debris, it was pretty intense,’ he said. ‘Lots of chaos.’

Mandy Tang, 38, from London, was in a cinema in Bangkok on holiday when she experienced the tremors from the powerful earthquake.

She told the PA news agency: ‘I was watching a film called The Red Envelope. It happened to be quite an action-packed scene when the shake happened, so I initially thought it could have been Imax effect.

‘I looked around and none of the local audience left their seats. However, my Taiwanese friend insisted it’s an earthquake, so I walked out of the theatre with her, and we met the security guards coming to evacuate us just outside the theatre. We could see the doors were opening and closing, all the chairs were shaking.’

The earthquake struck on Friday at midday with an epicenter close to Mandalay, followed by several aftershocks, including one measuring a strong 6.4 magnitude. 

It sent buildings in many areas toppling to the ground, buckled roads, caused bridges to collapse and burst a dam.

Myanmar is in the throes of a prolonged and bloody civil war, which is already responsible for a massive humanitarian crisis. 

It makes movement around the country both difficult and dangerous, complicating relief efforts and raising fears that the death toll could still rise precipitously.

In the capital Naypyidaw, crews worked to repair damaged roads, while electricity, phone and internet services remained down for most of the city. 

The earthquake brought down many buildings, including multiple units that housed government civil servants, but that section of the city was blocked off by authorities on Saturday.