Petra Nemcova recalls the deadly tsunami in Thailand 20 years later

Two decades after a devastating tsunami swept across Southeast Asia, Petra Nemcova remembers what and who helped her survive the storm.

The Czech-born supermodel talked about her vacation-turned-nightmare with ABC News’ Diane Sawyer in a segment that aired Thursday. “Good morning America.” Sawyer first time interviewed Nemcova on her improbable survival in 2005, just months after the storm cost more than her life 230,000 people – including Nemcova’s boyfriend, British photographer Simon Atlee, who was among the 5,000 who died in Thailand.

“It’s always hard to go back to the moment when my life changed,” Nemcova told Sawyer in Thursday’s segment, which included footage from their original conversation nearly 20 years ago.

Nemcova has previously described how the tsunami of December 26, 2004 had flooded the bungalow she and Atlee lived in – just as they were packing up to leave. Atlee was consumed by the water, but Nemcova managed to cling to a palm tree for eight hours before being rescued.

“I went into this stillness, almost like a meditative state,” the former “A Model Life” host said Thursday, “because I knew if I start panicking, you lose more energy. And I needed for all my energy to keep me alive.”

In the hours Nemcova was frozen, debris broke every bone in her pelvis and caused severe internal bleeding in her abdomen, ABC reported.

Because of her injuries, Nemcova could not swim, she said in 2005.

But then a group of strangers found her, Sawyer said in Thursday’s episode. They dressed her in new clothes, laid her on a mattress and steered the makeshift life raft towards medical attention.

“Those people were ready to risk their lives for strangers, and that shows the best of humanity,” Nemcova said Thursday.

The second part of the conversation with Nemcova will be broadcast on Friday morning. It will highlight the philanthropic work the model has done since the tragedy in Thailand and “turn all the darkness into light,” Sawyer said.

In 2005, Nemcova founded Happy Hearts Funda charity that coordinates disaster relief efforts beyond what emergency workers can provide. While competing on “Dancing With the Stars” Season 12 in 2011, the model performed a routine to Josh Groban’s “You Raise Me Up,” saying the song empowered her to found her nonprofit.