Experts have determined that even after five years of the devastating 2004 Indian Ocean tsunami that struck Indonesia, local communities are not well prepared to face such a disaster, despite the fact that the technology is in place.
On 26 December 2004, a magnitude-9.0 quake off the Indonesian island of Sumatra generated a series of tsunamis that drowned some 230,000 people around the Indian Ocean.
Most of them had no idea it was coming.
Memory of the disaster remains relatively fresh in many coastal communities, even in the South Pacific, where American Samoa and other nations have used it to brush up on their preparedness plans.
However, according to a report in Nature News, experts say that much work remains.
In all the world's major oceans, sophisticated tsunami-sensing instruments are now on alert, from the extensive Pacific network first set up in 1965 to the brand-new system deployed across the Indian Ocean in the wake of the 2004 disaster.
Such systems rely on a network of seismic stations to detect the earthquake, and deep-ocean and coastal gauges to detect resulting changes in sea level.
But, the best instrumentation in the world cannot guarantee that crucial communication takes place where it is needed: at the waterfront, before the wave strikes, and in terms that local communities can understand and heed.
"In the Indian Ocean region, there is a tremendous amount of work yet to be done," said Costas Synolakis, director of the University of Southern California's Tsunami Research Center in Los Angeles.
"It is urgent work, because when it comes to tsunamis, bad information kills," he added.
Before 2004, most people associated tsunamis with the Pacific Ocean, where the waves have repeatedly struck Japan and Hawaii.
Few worried about such hazards in the Indian Ocean.
Only 4 percent of all known tsunamis in the twentieth century occurred there - and none had struck in living memory in countries such as Thailand, India and Sri Lanka.
Palaeorecords of ancient tsunamis suggest that the 2004 event was the biggest in that region in more than 600 years.
But, with the development of the new Indian Ocean Tsunami Warning and Mitigation System by the end of March 2010, people would be more aware and a lot safer than before.
"People in the region are safer than they were in 2004," said Keith Alverson, project-office director with the Global Ocean Observing System of the United Nations Educational, Scientific and Cultural Organization (UNESCO) in Paris.
"The challenge is to tailor technology to local cultures and make the system sustainable in the long term," he said.