The scale of the devastation unfolded over the coming hours and days, with the death toll rising sharply into the thousands as rescue workers in both countries retrieved bodies from the wreckage of demolished apartment blocks.
In opposition parts of Syria, civil defence teams - namely the White Helmets - were hampered by a litany of obstacles, namely inadequate resources, border closures, roads ploughed up by aftershocks, and the bitter cold.
The response to the tragedy was compounded by severe damage to infrastructure in the southern Turkish city of Gaziantep, which was in the vicinity of the earthquake's epicentre and also where many NGOs operating in northwestern Syria are based.
For days, apartments and offices were evacuated as concurrent aftershocks rumbled on, toppling buildings and showering streets with falling masonry as the city's population sought shelter in cars, basements or mosques.
"Syrian NGOs based out of Gaziantep are the first line of defence and usually the first to respond in previous cases of widescale destruction are also hit, they themselves are in a precarious situation," said Sinan Hatahet, a senior research fellow at the Syrian Forum.
"Syrian NGOs mostly lack the resources to conduct their rescuing operations. They don’t have enough machinery at their disposal and lack the funds to rent them out or operate them. There is also a cruel lack of fuel for heating purposes too."
The latter led to makeshift fires being built at the sites of collapsed buildings, to warm rescue workers and families as they searched through the night for loved ones.
"Northern Syria's infrastructure is poor and it isn't prepared for a natural disaster of this magnitude. There are no shelters, not enough first response teams and no central government agencies to intervene. The Syrian people and NGOs are left to their own devices to intervene," Hatahet added.
"The Turkish agencies are also overwhelmed by the earthquake, their help and assistance in Syria are delayed by the sheer volume of destruction in their hometowns.
"ADAD is planning to open an air aid corridor to northern Syria and has already started to collect names of Syrian and Turkish volunteers to intervene."
Almost every NGO worker The New Arab spoke to while researching this story said they had lost colleagues in the tragedy, a harrowing experience where the helpers themselves were in mourning.
The International Rescue Committee (IRC) and other NGOs had to assess the safety of their staff before rushing teams to danger zones, despite thousands being trapped under the rubble.
"The IRC is currently running a rapid needs assessment to see how best to support affected populations," said Elias Abu Ata, Regional Senior Media and Communications Manager, IRC Middle East and North Africa.
"Our priority now is working to ensure the safety and security of our staff in Turkiye and inside Syria, as well as that of our partner organisation."
The quake had turned well-paved highways in Turkey's Hatay province into brittle shards of tarmac making the border area impenetrable, isolating northern Syria from the outside world.
"It's going to be very difficult [to work in Syria] because the infrastructure in southern Turkey has been damaged badly - Hatay and Gaziantep airports are closed and highways, especially in Hatay, have been damaged," said Suhail Al-Ghazi, a Syrian researcher.
"The NGOs will face more risk in delivering aid to inside Syria if their operations in Turkey are damaged."
Bab Al-Hawa, the only border crossing from Turkey into northern Syria, closed due to the destruction, meaning Idlib and other opposition areas were left alone to deal with the crisis.
Turkish authorities opened the Bab Al-Asalama and Alraee gates into Syria on Wednesday while Bab Al-Hawa border will open on Thursday, sources told The New Arab.
When Bab Al-Hawa opens, there will be the added logistical challenge of thousands of tonnes of machinery and aid making their way through the crossing, after Russia and China used their vetos at the UN to close other border points into non-regime-held areas of Syria.
The massive devastation on the Turkish side of the border has put pressure on scant resources with Syrians fearing they will be the worst off.
Turkey's President Recep Tayyip Erdogan is facing the biggest challenge in his political career in this year's general election with a face-off against a united opposition amid a backlash over his handling of the earthquake and years of anti-Syrian sentiment in the country.
"The disaster will force the Turkish government first to avoid anger from the population but I think aid to Syria will be facilitated by the government," said Ghazi.
"[Turkish Armed Forces] vehicles are already involved in helping in Idlib for example."
Idlib was already struggling to cope after years of targeted airstrikes destroyed clinics and hospitals in the opposition province and killed scores of medics and first responders, along with devastating other critical infrastructure.
"The relief efforts inside Syria are not able to cope right now. Some of the hardest hit areas are where hospitals and clinics collapsed or were affected, including Jandairis where we have a hospital," said Amany Qaddour, Regional Director at Syria Relief & Development, told The New Arab.
"We're working hard to mobilise but our own responders have been impacted too."
Enter the heroes
Idlib has been blessed with the professional and courageous work of the White Helmets, who have worked to rescue survivors of air strikes and shelling throughout the war.
One heartwarming video showed two small children being rescued by the rescue workers when their home collapsed in Idlib. The brother and sister were lifted into the air to the cheers of a crowd who had gathered around the site praying for their safety.
Their years of experience digging bodies out of homes and hospitals levelled by air strikes have prepared them for the grim task, but even they say the current situation is unprecedented.
"This is one of worst days as the White Helmets... with this big disaster, this number of workers is so small," said Mohammed Al-Shebli, spokesperson for the White Helmets told The New Arab.
More than 1,048 homes were partially damaged and 378 buildings were destroyed in northwestern Syria by the quake.
The White Helmets, which has rescue centres across Idlib, has around 2,600 workers on the ground, but say this number is too small to properly deal with the situation.
Al-Shebli said this means there is an urgent need for help from the outside world, with rescue teams, sniffer dogs, and machinery, particularly in need.
The morbid reality is that those buried under the rubble are entering a death zone period when each hour that ticks by reduces the chances of survival.
"We have been working continuously for 61 hours now, so the vehicles will not work for a long... the main question we have is time, when will [the international community] come to northwestern Syria, when will they support Syrian organisations, when will they help the Syrian people?" Al-Shebli said.
"It is not the first earthquake in the world, so all the rescue teams and international organisations know how to respond to this incident, but there is no decision from the UN yet, and there is no plan yet. We want to know what will you [the world] provide for us [in Syria], and when?"
Syrians in the diaspora mourned the dead everywhere, many having family in both opposition and regime areas of the country, calling for urgent assistance to Syria.
"I think international assistance is urgently needed in Syria, where equipment is either insufficient or inoperable, and experienced cadres are also needed, to dig for possible survivors under the rubble," Dima Moussa, an opposition member of the Small Body of the Syrian Constitutional Committee, told The New Arab.
"Medical assistance is also needed for the injured. Not to mention the massive number of homes and buildings that have been levelled, which means a huge number of people without shelter, especially in this weather."
Paul McLoughlin is a senior news editor at The New Arab.
Follow him on Twitter: @PaullMcLoughlin