First, the bottom floor crumbled.

Then the rest of the building came down on top of it in what's known as a "pancake collapse".

Thousands of buildings near the epicenter in southern Turkey and northern Syria tumbled straight down in a similar way.

The intensity of the earthquakes alone carried the potential for destruction.

But it's the pancake collapses that have made this one of the deadliest disasters in the region.

Even in very well-designed and executed building would have suffered.

This doesn't rule out that the buildings were free of defect.

"How well buildings protected residents played a significant role in lives saved and lost."

"Clearly a lot of these buildings were not up to standard."

The death toll continues to climb as many victims are still stuck under the weight of the buildings.

So what is it about these buildings that has made this earthquake even more devastating?

First, let's look at the larger region that's prone to severe earthquakes because of these two fault lines.

They sit along tectonic plates that meet one another and cause friction.

When the friction builds up, a powerful earthquake is eventually released.

Over the last century, Turkey has seen major earthquakes along both fault lines.

The most recent one happened here.

This is the seismic impact that shows the epicenter.

When you take a closer look at the most impacted areas, they were densely populated with Syrian refugees who ended up living in buildings that were haphazardly built and largely neglected.

And across the border in Syria, buildings in these areas were already weakened by the prolonged civil war.

But what really complicates this disaster is that Turkey was aware of the buildings that were the most high risk.

They're called soft-story structures.

A soft-story building is typically a large structure with multiple floors and an open plan on the bottom.

That bottom floor can sometimes be a parking garage space for small businesses or extra homes.

These buildings are very common throughout the world, especially in countries like India, Pakistan, and Turkey.

Because they offer a solution to overcrowding in densely populated areas.

But they historically do a poor job of withstanding medium to powerful earthquakes.

Here's why:

These columns here are usually made of wood and the stories on top might be made of heavier materials like concrete.

Sometimes the bottom floor has fewer walls than the ones above with sides that may be left open or columns that aren't connected by walls.

This means that a soft story is the weakest floor and cannot fully support the heavier ones above it.

So when an earthquake hits, the structure may shake, until that bottom floor collapses.

During powerful earthquakes like Turkey and Syria's, the remainder of the building may follow.

This kind of collapse traps people under heavy construction materials making rescue missions even more difficult.

But this is a challenge Turkey has faced before.

A comparable 7.6 earthquake hit Izmit in 1999 and caused over 17,000 deaths.

It became clear that poor building design and soft stories which made up nearly 90% of building collapses exacerbated the death toll in this disaster.

The aftermath pushed the Turkish government to reintroduce building codes with an emphasis on earthquake safety.

But they weren't enforced due to corruption.

And many buildings in Turkey were built too well before 1999, which meant those buildings could only be strengthened retroactively.

There is a way to keep soft-story buildings intact in the event of an earthquake: retrofitting them with materials that can support the weight of the structure.

In an ideal scenario, these wooden columns can be replaced or reinforced with steel frames.

These open walls can be reinforced too and extra bolts and braces can be drilled into the foundation.

So if the structure shakes, there's support from that bottom floor.

A solution like this seem simple, but it's extremely expensive to execute.

According to the World Bank, around 6.7 million residential buildings in Turkey need retrofitting or reconstruction at a cost of $465 billion.

As of 2021, only about 4% of those buildings were transformed.

In fact, retrofitting is an expensive undertaking and nearly impossible, even in countries like the US.

Here is every remaining soft-story building in San Francisco that needs reinforcements that would cost billions.

But another problem in Turkey is that construction companies have been cutting corners and ignoring building codes for decades.

And the Turkish government has let their violations slide.

According to the BBC this post advertised a building that complied with Turkey's latest earthquake safety regulations which emphasizes the use of strong materials.

But the way that same building collapsed suggests it was a soft-story structure.

Now, Turkey is cracking down on contractors that are allegedly responsible for these collapses.

The scale of this disaster is a result of complex factors,

like geography, neighborhoods still reeling from war, and weak buildings.

But what makes this moment particularly harrowing is that while earthquakes along fault lines are inevitable, many of these deaths didn't have to be.

Turkey, along with other countries near fault lines are all prone to intense earthquakes.

But they won't have to be this deadly if cities enforce codes and treat safe housing as a human right.