MENTAWAI regency in West Sumatra shook like a leaf on Monday last week. It took minutes for huge waves as high as coconut trees to reach 600 meters onshore. The administration of Mentawai listed 408 dead and more than 128 people missing. Tempo describes the seconds before the tragedy took place. If the residents were unable to help themselves, it could be because the Tsunami Early Warning System on the western shores of Sumatra failed to work. What really happened