Chilling footage captures the initial waves of ocean tsunami that killed 220,000 people

An innocuous video of a man lounging on a beach in Thailand chillingly captured the first waves of a tsunami that killed more than 200,00 people.

The day after Christmas in 2004 in the region would go down in history due to a devastating earthquake that erupted underneath the Indian Ocean.

The quake took place just off of the coast of the Indonesian island of Sumatra.

As it happened under the water, it caused a tsunami of ocean waves that devastated many nearby countries.

The earthquake was on 9.1 magnitude, making it the third largest in the world since 1900, and it occurred 18 miles underneath the ocean's surface, as two tectonic plates collided.

The rupture created between the Indian and Burma plates was 800 miles long.

It wasn't just felt in Indonesia as Bangladesh, India, Malaysia, the Maldives, Myanmar, Sri Lanka, and Thailand all reported the earthquake.

Thailand was devastated by the massive tsunami. (Patrick AVENTURIER/Gamma-Rapho via Getty Images)

While the earthquake was powerful, it was the resulting tsunami that really caused devastation to India and Indonesia.

Within 20 minutes of the quake, waves of water began to hit the coasts of surrounding islands.

In Indonesia's Aceh province in Northern Sumatra, waves reached 167 feet and caused floods for three miles.

Following the tsunami, an astonishing 227,899 were killed or missing and presumed dead, including tourists and locals.

This made the 2004 Indian Ocean tsunami the most deadly in history.

On top of this, more than 1.7 million people were left without homes, and total damage was estimated at roughly $13 billion.

But what ended up as the most deadly tsunami of all time unbelievably started with just a few small waves.

And even more shockingly, an unknowing tourist actually managed to capture these first few waves on video.

A man unknowingly captured the first waves of the tsunami. (YouTube/Julian Hadden)

In the clip, a man says: "We were supposed to go caving this morning, had just about booked it.

"But then, look, waves."

He gestures to the ocean where some moderate waves are picking up.

Later, the waves begin to look more serious, even knocking over a beach chair.

A boat is also seen rocking in the water as the tourists begin to clear the beach.

Julian Hadden, who posted the footage on YouTube ten years ago, thankfully confirmed that everyone in the clip survived the tsunami.

He said in the caption: "In response to the many questions - all of us featured in this video are still alive.

"We were on the landward side of the island of Koh Ngai, Thailand, so didn't get a direct hit - rather the wave as it washed around the island."

It's truly horrifying to know that these initial small waves could lead to the kind of devastation seen in the 2004 Indian Ocean earthquake.