Two Indonesian tsunami warning buoys, put in place after a 2004 earthquake and tidal wave killed more than 230,000 people, failed to activate on Oct. 25 when a 7.7 magnitude temblor hit the country’s Mentawai Islands. This time, more than 400 died.
Even if the buoys had been operational, islanders would not have had enough time to evacuate, since the earthquake that triggered the tidal wave occurred too close to shore, according to the U.S. National Weather Service.