Petra Nemcova remembers the deadly tsunami in Thailand 20 years later

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

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

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

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

“I fell into this stillness, almost a meditative state,” the former “A Model Life” host said Thursday, “because I knew that if I panicked, you lose more energy.” And I needed all of it Energy to stay alive.”

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

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

But then she was found by a group of strangers, Sawyer said in Thursday’s post. They dressed her in new clothes, laid her on a mattress and steered the makeshift life raft toward medical help.

“These people were willing 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, “turning all the darkness into light,” Sawyer said.

In 2005 Nemcova founded the Happy Hearts Funda charity that coordinates disaster relief efforts that go beyond what emergency responders can provide. The model was a model while competing on Season 12 of Dancing With the Stars in 2011 performed a routine to Josh Groban’s “You Raise Me Up” and said the song empowered her to start her nonprofit.