People gathered in prayer and visited mass graves in Indonesia's Aceh province on Thursday to mark 20 years since the massive Indian Ocean tsunami hit the region in one of modern history's worst ...

“The Indian Ocean tsunami 20 years ago has reshaped the way the humanitarian community addresses emergencies today, highlighting the importance of disaster preparedness,” a European Union ...

When the tsunami inundated the coasts of more than a dozen Indian Ocean nations on Dec. 26, 2004, about 230,000 people lost their lives. Entire communities were erased.

Experts said they were “blind” to the Indian Ocean tsunami in 2004. Twenty years later, working toward a world without tsunami deaths is a challenge.

In the years since the Boxing Day tsunami, countries at risk have invested in “hard” engineering defences including seawalls, offshore breakwaters and flood levees.