The largest earthquake in the past 40 years and the resulting deaths of thousands from 33-foot tidal waves are being compared by an American reporter to descriptions of disaster from Holy Scripture.

"The speed with which it all happened seemed like a scene from the Bible – a natural phenomenon unlike anything I had experienced before," said Washington Post reporter Michael Dobbs, who was swimming off a Sri Lankan island when the disaster struck this morning.

"As the waters rose at an incredible rate, I half expected to catch sight of Noah's Ark. Instead of the Ark, I grabbed hold of a wooden catamaran that the local people used as a fishing boat. My brother jumped on the boat, next to me. We bobbed up and down on the catamaran, as the water rushed past us into the village beyond the road."

Officials at the U.S. Geological Survey said the 9.0 quake, which centered off the Indonesian island of Sumatra, was the world's fifth-largest since 1900 and the biggest since a 9.2 temblor hit Prince William Sound Alaska in 1964.

The temblor sparked a tsunami, a series of giant walls of water which left more than 24,000 dead in ten countries, with the death toll continuing to rise.

Dobbs gives a first-person account of the dramatic event in the Post:

Disaster struck with no warning out of a faultlessly clear blue sky. ... I was a quarter way around the island when I heard my brother shouting at me, "Come back! Come back! There's something strange happening with the sea." ...

In less than a minute, the water level had risen at least 15 feet – but the sea itself remained calm, barely a wave in sight. ...

After a few minutes, the water stopped rising, and I felt it was safe to swim to the shore. What I didn't realize was that the floodwaters would recede as dramatically as they had risen.

All of a sudden, I found myself being swept out to sea with startling speed. Although I am a fairly strong swimmer, I was unable to withstand the current. The fishing boats around me had been torn from their moorings and were furiously bobbing up and down.

For the first time, I felt afraid, powerless to prevent myself from being swept out to sea.

I swam in the direction of one of the loose catamarans, grabbed hold of the hull, and pulled myself to safety. My weight must have slowed the boat down and soon I was stranded on the sand.

As the water rushed out of the bay, I scrambled onto the main road. Screams and yells were coming from the houses behind the road, many of which were still half full of water, trapping the inhabitants inside. Villagers were walking dazed along the road, unable to comprehend what had taken place.

I was worried about my wife who had been on the beach at the time I went for my swim. I eventually found her walking along the road, dazed and happy to be alive. She had been trying to wade back to our island, when the water had carried her across the road and into someone's back yard. At one point she was underwater, struggling for breath. She finally grabbed onto a piece of rope and climbed into a tree, while the waters raged beneath her.

An Italian scientist says the earthquake was so strong, it even disturbed the rotation of the Earth.

"All the planet is vibrating," Enzo Boschi, head of Italy's National Geophysics Institute said on SKY TG24 TV.

The U.S. State Department says at least three Americans are confirmed dead, two in Sri Lanka and one in Thailand.

A written statement from the White House says "the President expresses his sincere condolences for the terrible loss of life and suffering caused by the earthquake and subsequent tsunamis in the region of the Bay of Bengal.

"The United States stands ready to offer all appropriate assistance to those nations most affected including Sri Lanka, the Maldives, Thailand, and Indonesia, as well as the other countries impacted. Already relief is flowing to Sri Lanka and the Maldives. We will work with the affected governments, the United Nations, non-governmental organizations, and other concerned states and organizations to support the relief and response to this terrible tragedy."

Relief agencies say the full scale of the disaster is impossible to assess, since communications have been cut to remote areas.