His clothes had been ripped off by the surging wave. He survived because his nappy stayed on and became snagged in branches as the waters receded.
The Impossible, starring Ewan McGregor and Naomi Watts, uses graphic imagery to retell the story of one family's battle to survive after a 30m tidal wave smashes into the coast of Thailand on Boxing Day eight years ago. The movie, already a box office hit in other parts of the world, opens in New Zealand on January 24.
"Even the trailer is frightening and it brought our own nightmare straight back," Kathryn told the Herald on Sunday. "A scene in which the huge wave bursts into the grounds of a hotel and destroys everything in its path is very realistic."
The Morgans, who were working in Kuwait at the time, had joined two friends for a dream holiday in the Seychelles.
"It was so beautiful and we were so excited to be there," Kathryn said. "We were having a great time when I noticed the tide was getting unusually high.
"Then it was like someone had pulled a plug and the sea disappeared from the bay, leaving fish flapping around. It never occurred to me that all that water was bound to come back."
Transfixed, the couple watched in horror as a large catamaran started spinning around wildly out at sea. It was then Kathryn noticed the massive wall of filthy brown water heading towards the beach.
"People started screaming and running but there wasn't a thing you could do to escape it," Kathryn said.
The Morgans were swept out to sea and their baby vanished.
"A lot of people died in the tsunami because they panicked in the water," Kathryn explained. "We had learned to swim in dangerous seas in New Zealand and that really helped. All I could think about was my son."
In the chaos, the Kiwi parents were amazed to find each other alive. "I was convinced we would never see Willie again, then a young girl said she had seen a baby in the bush. We found Willie stuck up a tree and hanging by his nappy. He had turned grey but was breathing and suffered just scratches. We couldn't believe it."
The family now also have a daughter, Mackenzie, and moved back to New Zealand in 2006. Kathryn, 41, is deputy principal at Darfield High School. Brent, 47, is in electronics.
They have since experienced the Christchurch earthquakes but will never forget their brush with death in the Seychelles.
"We have watched TV documentaries about the disaster without too much trouble but The Impossible might be difficult as it is all very close to the bone," Kathryn added.
Survivors hit hard by disaster film trailer
Survivors of the Boxing Day tsunami were left in tears when cinemas screened the trailer for The Impossible without warning.
The 2004 disaster claimed the lives of more than 230,000 people, including seven New Zealanders.
The promotional video for the film took British tsunami survivors by surprise when shown without any prior notice before other popular films including Sir Peter Jackson's The Hobbit.
"There were scenes of people drowning and bodies floating about and it brought it all back so hard," one man told UK newspaper The Daily Mail.
Christchurch survivors Brent and Kathryn Morgan have already seen the trailer and have been invited to watch The Impossible at a special screening in the city on January 23, the night before it opens nationwide.
