If something good came out of the terrible Indian Ocean tsunami in 2004, apart from peace in Indonesia's Aceh province and the triumph of human spirit and compassion over unimaginable loss and suffering, it was an international resolve to build a warning system to give millions of people a better chance of surviving the next 'big one'. While hundreds died in Monday's tsunami off west Sumatra, experts agree that the really big one is still coming - any day in the next decade or two. The latest disaster is therefore a reality check on how much better protected people in vulnerable areas may be when it happens.
Even before it struck, engineers and seismologists were worried that the international community and Indonesian authorities had not heeded warnings and applied the lessons of that dreadful Boxing Day nearly six years ago. Sadly the evidence tends to support them.
The international community agreed to build an early warning system to give people time to flee to higher ground. With German aid, Indonesia completed a key part of its system - electronic buoys to detect sudden, tiny changes in water level - two years ago. But officials say it has broken down because inexperienced operators lack the expertise to monitor the buoys. Even if it had worked, six stations in West Sumatra designed to sound warning sirens 15 to 25 minutes before a tsunami makes land were knocked out by an earthquake last year that killed 1,000 people and remain unrepaired. Fifteen to 25 minutes may not seem like much of a start in trying to outrun a tsunami, but it is enough time for the average person to cover more than one or two kilometres at normal walking pace.
Indonesia doesn't have the problem on its own. Similar buoys deployed by the United States have slipped their moorings or suffered outages of their sensors. And to be sure, the people who suffered the most on Monday, in remote ocean-island communities close to the epicentre of the undersea quake that triggered the tsunami, are not so easily safeguarded. A centre of concern, however, is the port city of Padang, home to one million people in an area where two tectonic plates come together in the earthquake-prone Sunda ocean trench. This was the origin of the tsunami that killed about 230,000, including nearly 170,000 in Indonesia alone, in 2004. Geophysicists are critical of the lack of international co-operation to ensure that West Sumatra remains prepared for a repeat. And the UN Development Programme says the local disaster management plan is starved of funds, which have been used to help victims of last year's quake.
A plan by the local disaster management agency to seek help from the Asian Development Bank to design and build 100 solar-powered sirens along the West Sumatran coast by 2013, with 100 more to follow, is a step in the right direction. But Monday's tsunami is a reminder of the need for a greater sense of urgency all round.
The humanitarian effort after the Boxing Day tsunami was one of the international community's finest hours. History will write a tragic footnote if the lessons of that catastrophe are not learned. A focus on preparedness now could save thousands of lives in the future. Undeterred by official complacency, a non-government organisation in Padang has sent volunteers into schools to make disaster preparedness, including basic survival knowledge like evacuation, an extra-curricular subject. Attempts to make it part of the official syllabus have failed. That kind of initiative deserves more government support. After all, the odds against the next 'big one' will shorten as the younger generation grows up.