A decade ago, a huge tsunami ripped across the world, killing more than a quarter-million people in 11 nations. In Indonesia, thousands perished or lost their homes and businesses.

Ten years after this catastrophic event, there are vital lessons for coastal communities like Hawaii. Here are seven ideas we should not forget.

» First, we must invest in research on earthquakes and tsunamis.

This is especially important in the Pacific, which accounts for 80 percent of world’s largest earthquakes. The 2004 tsunami was triggered by a massive 9.0 undersea earthquake. With runup heights of over 10 meters, it first struck Aceh Province on the island of Sumatra, spreading to Malaysia, Thailand, India, Sri Lanka, Myanmar, the Maldives, and the African continent.

» Second, disasters highlight the value of education, training, exercises and drills.

Unfortunately, there has been tremendous growth and migration into hazard zones. Communities and their institutions, businesses, and organizations need to mainstream risk and vulnerability assessments, emergency response and recovery procedures, and preparedness training into their programs, budgets, plans, and policies.

A powerful lesson on the importance of traditional knowledge emerged from Simeulue island. Only 100 kilometers from the epicenter, it suffered massive damage, yet few fatalities. Local island culture stressed tsunami knowledge and evacuation. Generations of islanders were taught to yell "smong, smong, smong" and to run to the top of hills. Programs need to build on such local wisdom and integrate customs and culture.

» A third lesson involves detection and warning systems.

While the Pacific Tsunami Warning Center in Hawaii detected the tsunami within 18 minutes after it occurred, the response network and communications to affected areas was, at that time, extremely limited.

Since 2004, countries have invested in monitoring systems, deploying sensors and satellites, smartphones and social media networks to get out warnings. There is still need for better coordination and cooperation between governments, scien-

tific agencies, national and local emergency responders, NGOs, industry and communities.

» Fourth, the tsunami demonstrated the value of natural barriers such as healthy coral reefs, mangrove forests, wetlands, beaches and open space.

Many of the worst-damaged areas with the highest casualties occurred in over-developed coastal areas.

Reliance on sea walls and physical structures may have contributed to a false sense of security. Prudent coastal management will help build resilience.

» Fifth, people have an enduring attachment to place.

While a spectacular effort to build resettlement villages out of harm’s way was initiated in Banda Aceh — where 167,000 people were killed — there are strong desires to return home. We’ve seen this following the Katrina and Sandy hurrricanes and Typhoon Haiyan. It involves land ownership and where livelihoods are located. Unless businesses, schools, government agencies, health care, churches and mosques move to new areas, there will be driving forces to rebuild original sites.

That’s what makes the case of the 1960 Hilo tsunami so instructive. Creating open space and not rebuilding damaged areas, through the use of land swaps and redevelopment tools, stands out as exemplary practice.

» Sixth, disproportionate numbers of children, women, elderly and persons with disabilities were killed.

Disasters magnify existing weaknesses in society. Moreover, thousands of foreign tourists were killed in the Indian Ocean tsunami. There are vulnerable, at-risk groups we need to plan for in Hawaii and other coastal communities.

» Finally, remembrance is key to recovery.

Monuments, shrines and museums help us honor those who lost their lives and those who gave unselfishly in the rescue, response, relief and recovery efforts. Whether in Hilo, Samoa, Fukushima or Banda Aceh, these remembrances allow us to look back and also to move forward, signaling progress in healing and recovery.

By not forgetting the past, we can better prepare for the future.