Thousands of people have been e-mailing the BBC News website about horrific experiences as sea surges hit their homes and holiday retreats.
Troy Husum, a 28-year-old Canadian, was on holiday in Phuket, Thailand. He spoke of the devastation as the waves hit the town of Patong and how survivors are coping.
I felt the quake first at about 0915.
I went out on my balcony in the hotel where I was staying - it was a beautifully calm day - and talked to others on their balconies. The quake felt very slight so we thought little of it.
About 45 minutes later, I noticed that water had receded from Patong Bay. We'd never seen it before and we could hear people on the beach talking about it. You could even see fish flopping around on the beach, which was unusual.
I noticed small kids and tourists walking to where the water had receded, curious as to why the water had gone.
Then I saw it - I noticed people craning their necks and looking out on the horizon. You could see a wall of water about three or four stories high.
I felt like I was watching a movie, it was completely surreal.
It wasn't moving very quickly, it took between four and five minutes until I saw it hit and in that time slowly people started to realise what was happening.
People were saying 'Oh God, what is that?' I thought I was dreaming.
Most disturbing was I saw people literally disappear when the water hit... people were literally swept away
After a few seconds the wave hit and smashed against the beach.
It was incredible, it actually bent the trees, washed everything away - at least 1,000 beach umbrellas were swept along as all the water surged through.
There is a line of cars where people park by the beach and hundreds of bikes, I saw them all picked up like toys and moved along.
Most disturbing was I saw people literally disappear when the water hit.
I saw a lot running, but there were people snoozing on the beach, I saw small children hit. People were literally swept away.
A lot of injuries occurred from people being hit by debris from cars, from bikes.
Running for safety
I thought I should get some pictures because I was staying on the fourth floor of my hotel, but other people on the balconies said we had to get on the roof.
I grabbed my equipment and ran outside into the hall. People were screaming "Go! Go!" I ran up the stairs and saw the water coming.
It flowed up to the third floor, you could see it in the stairwell, some people were completely wet.
We watched the chaos from the roof. The water had already started to recede as we got there.
The hardest part for survivors was actually when water receded - the undercurrent sucked people back into the ocean.
The most frightening part was not the wave - it was the panic that ensued.
There were car accidents, people were trying to escape as everyone was positive another wave was coming.
They are still pulling people out of the debris, one was a small Thai girl - she must have been there all night but she was still alive
People - mainly local Thais - went up the roads to the mountain and slept up there for safety.
Within an hour I went back to the beach. I saw bodies. The rescue crews were panicking and there was not much control.
Bodies were pulled from the debris - most had clearly drowned. I also saw a number of fractures - one tourist had a very badly broken arm.
You could constantly hear helicopters - they flew up to about one kilometre out to sea to try to rescue people.
Last night most hotels allowed tourists to sleep for free in their lobbies or by the pool and there was still a lot of fear and misinformation about other waves.
This morning the cleanup started. All the foreigners are in disbelief, there are two or three feet of sand in all these devastated restaurants.
There are piles and piles of rubble deep inland - it looks like a bomb has gone off.
Some bars I went to the night before on the beach are completely gone,. All of the palm trees were flatted or removed. How is water capable of doing that?
They are carting out hundreds of cars and bikes and the streets are still covered with sand.
They really should have cordoned off the streets. There has been a little looting, some last night and today. I saw guys with televisions and computers.
There are people staggering around with injuries, I saw a girl with bandage on her head. Today there have also been sirens which have now died down.
They are still pulling people out of the debris. One was a small Thai girl - she must have been there all night but she was still alive.