The story broke, like the tsunami itself, with a rumble that was portentous but gave little idea of the scale of what was to unfold. It was 1.59am (UK time) on Boxing Day when an 18-word alert was dispatched by a bureau of the Associated Press in Jakarta. "A seismologist says a massive earthquake rocks Indonesia's northernmost province of Aceh, causing dozens of buildings to collapse."
One minute later, a four-paragraph report emerged from Reuters staff in Indonesia, where deputy bureau chief Dean Yates had been monitoring the state Antara news wire. That was the start of a head-to-head battle between the world's biggest news agencies to provide the most comprehensive coverage of the most important natural disaster story of modern times.
Yates's report - referring to "thousands of people" fleeing their homes and "widespread panic" - upped the importance of the story to international news desks around the world.
But Reuters' Jakarta bureau chief Jerry Norton, who was to spend the rest of the week working relentlessly on the story, says that his team were at first unsure of its significance: "I don't think there was necessarily an atmosphere of instant excitement, because Indonesia is earthquake-prone."
Because of the remoteness of Aceh - and the high levels of security in what is a closed militarised zone - it had taken a full hour between the initial earthquake and the first AP alert. There was no immediate indication of any casualties and, in global terms, the story was of limited interest.
John Whitney, duty news editor at BBC News 24 that morning, recalls the first stories about the disaster dropping on the agency wires. "I remember a flash saying there was an earthquake. I often read stuff where there are tremors off the coast of Japan and no one injured. This didn't feel any different in the beginning."
At 2.57am came another AP alert, which suggested the sea may have played a role in what had occurred. "Witnesses say earthquake in north-western Indonesia triggers large waves along coast; some damage reported" was the 14-word snap. Eleven minutes later AP sent a lengthier dispatch. It gave the first indication that the story was an international one: "The quake was felt as far away as the Thai capital, Bangkok," it said.
Still, there were no confirmed casualties. Then at 3.22am, nearly two and a half hours after the quake, AP stated: "Local radio station reports nine dead in earthquake in northwestern Indonesia." Seven minutes later, Reuters had the same figure and reported sightings of bodies in "flash floods".
At this stage, AP was making the running on the story, reporting at 4.11am that the quake had registered 8.5 on the Richter scale (Reuters had 6.4 at that point). But as other regions became part of the story, Reuters came back strongly. A piece from its Chittagong bureau reported panic in the Bangladeshi port. Then at 4.50am, the London-based agency introduced the T-word that has become synonymous with this story. From Colombo, Sri Lanka, it reported: "At last (sic) 10 people were killed after a tsunami triggered by an earthquake..." The typographical error seemed to capture the growing sense of alarm.
Reuters used the term "tsunami" 43 times before AP - which had previously preferred the expression "tidal waves" - deployed the word for the first time in a report from Australia at 8.44am.
Reuters was also first to report that India had become part of the story, with the Bombay bureau sending details of waves battering Madras. It also brought the first news of mass deaths when at 5.04am the Colombo office reported that at least 150 people were known to have died. By then, the news-wires were ticking over relentlessly with fresh dispatches. Adrian Wells, head of foreign news at Sky News, had been woken by night editor Gerrard Williams at 4am because of the growing importance of the disaster. Wells says the two agencies (as well as Agence France-Presse) "were all filing early and pretty well".
The Independent picture desk received its first shot of the disaster at 6.51am, when AP's Eranga Jayawardena filed a picture of villagers stranded on a Sri Lankan beach. Two minutes later, a Reuters image from a stringer in a helicopter over Phuket showed dramatic scenes of swirling waves.
Howard Goller, Reuters' editor-in-charge of World Desk, arrived at work at 7.30am. He had gone to bed expecting to be focused the next day on covering elections in Ukraine. But it soon became clear there was only one story in town, and it wasn't in Kiev.
The working atmosphere was so intense, he says, that he "didn't have the time" to take as much notice as he usually would of the rival agency AP. But Goller says he was gratified by the number of credits Reuters was receiving on the "ticker" scrolling across the Sky News screen in the newsroom.
More than a week later, the battle between AP and Reuters over coverage of the tsunami is still ongoing. But they now have another rival in the field of international news gathering.
By 5am in London, the BBC was learning of the importance of the story, not from the global news agencies but from the relatives of holidaymakers. At News 24, Whitney began to field a succession of phone calls recounting horrific tales from resorts in Thailand and Sri Lanka. One caller said his father had watched as 50 bodies were swept down the Sri Lankan street where he was staying. Callers like Mary Pickering, a senior BBC staffer who rang in from Phuket, were put on air to report from the scene.
"Never before have I worked on a story where the news was coming more from the public than the agencies," says Whitney. "When you take 10 calls from all over the country at five o'clock on Boxing Day morning, you know it's a big story. People were saying, 'My daughter has been washed away and is lucky to be alive - why aren't you covering this?' From the British point of view we had a new agency: the public."
Immediacy of amateur footage comes into its own
Never before has there been a major international story where television news crews have been so emphatically trounced in their coverage by amateurs wielding their own cameras.
Producers and professional news cameramen often found themselves being sent not to the scenes of disaster to capture footage of its aftermath, but to the airports where holiday-makers were returning home with footage of the catastrophe as it happened.
Sandy MacIntyre, the director of news for AP Television News (APTN), an agency that supplies 500 broadcasters worldwide, says: "The growing number of people in the world who have their own cameras means that the very first thing we are going to look for is someone with a camera who was there and filmed it, because we cannot get there quicker than they did." According to MacIntyre, "all the pictures of waves hitting have been filmed by amateur cameramen".
APTN instructed its staff to hunt down amateur footage. "We have been out actively seeking this stuff," he says, "with producers questioning every person they came across and staking out all the airports for people coming back from Colombo and Phuket."
MacIntyre says that in the first five days after the catastrophe, at least 10 pieces of amateur footage had been circulated to broadcasters around the globe. "Our guys in Colombo bumped into an English couple in their hotel and they showed them some great pictures," he says. "This is how it has happened."
The BBC also instructed its producers to try to bring back pictures taken by holiday-makers as they arrived home on flights to Heathrow and Gatwick airports last Monday. John Whitney, news duty editor, says that the BBC was sent pictures of the disaster by holiday-makers and their relatives via mobile phones and emails. MacIntyre says amateur footage was particularly important in the tsunami story because many of the tourists in key locations, such as Thailand and Sri Lanka, were likely to be wealthy enough to afford good camera equipment.
He says that in previous stories where amateur film had been involved, there was usually only a single piece of footage and money was often demanded for its use. With the tsunami disaster, the amateur footage is still emerging days later and no one is asking to be paid.