In downtown Tokyo, state broadcaster NHK was airing the dull debates of a Parliament night sitting when all hell broke loose.
To the sound of chimes, an urgent alert flashed upon the screen: "This is a tsunami warning."
Just under nine seconds before, Japan's world-famous earthquake early warning system had detected the first P wave of a massive 9.0 megathrust earthquake.
This almost instantly triggered a live warning, relayed direct to televisions across the country.
Beneath the Pacific Ocean, about 72km east of the picturesque Tohoku coastline, the subduction of one tectonic plate beneath another had sparked a violent quake that lasted for six minutes.
Within five minutes, seismometer data calculated tsunami height and arrival time for each point of the coast.
Tohoku's capital of Sendai got its first warning just three minutes after the alert.
Eight hundred people would soon die when a wall of water surged through its seaward suburbs and across its airport.
Minutes before 3pm, the tsunami warning was extended to the entire coastline.
When the monster arrived, its highest waves reached more than 30m in some places, and its immense force sent it rushing kilometres inland, tearing through ports and cities.
NHK began broadcasting surreal live footage captured by circling news helicopters: fields and suburbs being swallowed by an unstoppable black mass, within it ripped up homes, fishing boats, wreckage and logs swept along like matchsticks.
Vehicles bobbed along in the current, many coming to rest in windows of high buildings, and fires broke out.
In seaside towns like Hachinohe in Aomori prefecture and Kesennuma in Miyagi prefecture, large ships were picked up and dumped atop the remains of buildings.
At the Myagi city of Inshomaki, 70 of 108 pupils of Okawa Elementary were killed while trying to evacuate across a river bridge, the call to move to higher ground having been made tragically too late.
More than 3000 perished in the small fishing city, which young NHK reporter Ayumi Yanagisawa had managed to flee before it hit.
"Everything was destroyed," she said. "I could think of only one thing - I have to record it."
The camera rattled and cracks began to open up on the road beside her as live footage was streamed through NHK.
Whole houses were carried down a river before her. One man told her his mother was missing inside one.
"At that time, I could fear nothing, I wasn't scared. I realised my trauma just after one year."
The Tokyo offices of the Japan Meteorological Agency, known as the JMA, went into a frenzy after the buildings finally stopped shaking.
"It shook for a long time," said Takeshi Koizumi, the agency's senior co-ordinator for international earthquake and tsunami information.
"It was very scary."
Mr Koizumi said that, despite constant warnings and a long, violent earthquake, many had chosen not to move to higher ground, often because of misplaced trust in seawalls.
They were soon horrified to see water gushing over the top of the structures.
In other cases, people took notice of the first warning but did not pay attention to later updates.
A later study found that only about half of residents in the coastal areas in Iwate, Miyagi and Fukushima prefectures had heeded the warnings.
Most who evacuated survived.
The disaster would claim the lives of nearly 16,000 people, with several thousand still missing.
Most died as a result of drowning, the rest either crushed to death, or perishing from burns and internal injuries.
Official figures also showed more than half of the victims were older than 60, as were about three-quarters of those still listed as missing.
More than a million buildings were damaged - 129,000 collapsing completely - but rigorous building codes meant only a few perished as a result of the initial earthquake.
The total cost of the catastrophe has been put at $286 billion by the World Bank, making it the most expensive disaster of all time.
The blow was enough to prompt the Bank of Japan to offer $221 billion to the banking system to help offset the market fallout. Nearly three years on, the country is still cleaning up.
It is expected that by the third anniversary, nearly 12.6 million tonnes of disaster debris would have been processed and disposed of.
There were still nearly 300,000 evacuees on the Reconstruction Agency's books, although this figure had dropped from 470,000 and just 0.1 per cent remained in evacuation centres.
Almost all of more than 2300 school facilities have been restored, and industrial production capacity of the disaster-hit areas has almost recovered to pre-disaster levels.
The hard-hit agriculture, fishing and tourism sectors have gradually got back to business and it's expected the reconstruction of all of Japan's seafood processing plants would be complete within three years.
Of the 21,480ha of farmland ravaged by the tsunami, more than half is now ready to use again.
But all of this progress hasn't diverted attention from the disaster's worst lingering headache - the crippled Fukushima Daiichi nuclear power station.
The wrecked plant and its trapped contents have loomed over Fukushima prefecture since tsunami floodwaters knocked out the plant's back-up generators that were supposed to keep cooling its nuclear fuel.
The over-heating sparked meltdowns in three reactors and forced 150,000 to flee.
Tens of thousands are still unable to return home to areas contaminated by radiation.
The plant's embattled operator, Tokyo Electric Power Co, or Tepco, meanwhile remains at the centre of a never-ending public furore over its bungled handling of the crisis.
Fresh outrage came when the company recently confirmed contaminated water may have flowed into the Pacific Ocean.
Tepco has now begun the year-long recovery of 400 tonnes of highly irradiated spent fuel from a damaged reactor building, while the Government commits billions of yen to getting displaced residents back to Fukushima.
All the while, calls are growing for Prime Minister Abe to end nuclear power in Japan as the Government faces the controversial question over how many of its 50 undamaged reactors will be restarted.
The anti-nuclear movement was last month given weight with the backing of former Prime Minister Junichiro Koizumi.
"Leakage is contributing to increased environmental awareness and this is something we see every day on the news," said Hideyuki Ban, secretary-general of Japan's Citizens' Nuclear Information Centre.
Mr Ban said about 26,000km of land had been contaminated as a direct result of the nuclear accident.
The shoddy handling of the issue has also put a dent in public trust in the government.
Meanwhile, other agencies have reviewed their own successes and failures since the tsunami.
The JMA has improved its observation system to withstand the power blackouts during the event, installing three new tsunami detection buoys that would give faster and more accurate data.
The NHK, which has the responsibility of official emergency broadcaster, will also use more urgent language to get people to evacuate.
Tohoku earthquake and tsunami
What: 9.0 undersea megathrust earthquake, tsunami reaching heights of up to 30m, nuclear power plant meltdown.
Date: March 11, 2011.
Affected areas: Northeastern Japan, primarily Tohoku region.
Fatalities: 15,883 (2651 missing).
Cost: $286 billion.
The series
Monday: China's fight against earthquakes
Yesterday: New York after Sandy
Today: Japan's tragic lesson
Tomorrow: Tohoku: life in the aftermath
Friday: New Zealand: living with disaster.
