Brian Brant

"Knowing that we are still here and together, more importantly, would be some comfort," Louis Mullan tells PEOPLE

Louis Mullan and his brother Theo were taken in by a neighboring family in England after their parents died in the world's deadliest tsunami in history on Dec. 26, 2004.

"I don't mind telling the story of what happened to me on the day," Louis Mullan tells PEOPLE in this week's issue

Louis Mullan is speaking out after he and his brother survived the December 2004 tsunami that killed their parents.

AN ESTIMATED 230,000 PEOPLE DIED IN THE UNPRECEDENTED CATASTROPHE. NOW SOME OF THE FEW WHO MADE IT OUT ALIVE ARE SHARING THEIR POWERFUL AND PAINFUL LESSONS

It's been nearly 20 years since a catastrophic tsunami wreaked havoc on at least 12 countries and killed 230,000 people — Dendy Montgomery, of Indonesia, was one of the survivors, although many members of his family weren't as lucky.

"It's hard [for the younger generation] to understand that it wasn't so easy," she tells PEOPLE in this week's issue

Rachel Hearson learned "I can be strong in a situation like this, and I can be there for other people if I'm needed," she tells PEOPLE in this week's issue

"I could not ignore them," Thuleewan “Kimmy” Boonyarattana tells PEOPLE in this week's issue

The niece of a woman whose body was found in a creek about a quarter of a mile from where her vehicle crashed in Indiana three days after she went missing has questions surrounding the circumstances leading to her death.