A Swedish tsunami survivor at Phuket airport. (Reuters)

Sydney, Dec. 31: A mother who was swept away by the tsunami knew she could not hold on to both of her young boys and had to decide which one to let go of.

?I knew that if I held on to both, we would all die,? said Jillian Searle, from Perth, Western Australia. ?I had to let go of one of them and I just thought I?d better let go of the one that?s the oldest.? As her strength waned, and still clinging to her two-year-old son, Blake, she appealed to a woman nearby to grab hold of five-year-old Lachie. Although the other woman tried to hold on, she was forced to let go and the boy slipped from her grasp in the water.

?I pleaded with a woman to take hold of Lachie,? Searle said. ?When we saw her later she said: ?I?m really sorry, I had to let go of him?.?

A short time earlier, Searle and her husband, Brad, had just finished breakfast and were planning to spend the day with the boys beside the pool at the Holiday Inn in Phuket, Thailand.

Brad Searle went upstairs to find a swimming nappy for Blake while his wife stayed by the pool with their sons. Her husband never made it back down. He could only stare in horror from a first-floor balcony as the sea swamped the resort.

As Brad Searle tried frantically to wedge open a fire-escape door with a crowbar, he could not have known the decision his wife was being forced to make as she and the boys were swept up by the wave. Jillian Searle knew that Lachie could not swim and was afraid of water. But she knew that the wave was too powerful for her to try to hold on to both. Brad Searle managed to wedge open the door and ran downstairs, convinced that the tsunami had killed everyone in its path.

?The water had gone in and just rushed back out again and it was so horrific that when I got out to the front of the hotel I thought they were all dead for sure,? he said. But he found his wife and youngest son outside. All three took refuge by climbing on top of play equipment in the grounds of the hotel while the water surged around them. Then they climbed down to look for Lachie.

?We thought he was dead. It was the most horrible time of my life,? Brad Searle said. Two hours later, he found his son safe and well. Lachie had managed to stay alive by holding on to a door handle, his head just above the water.

?He told us that he was dog paddling as fast as he could because that?s all he knew,? Brad Searle said. ?When he let go of the handle the water had become shallower and he was able to get out.?

Lachie was then rescued by a security guard. ?He was so brave. We cannot believe how lucky we are,? Searle said. With mud marks up to his ears, Lachie?s first words to his father were: ?My hands are all dirty and I need to wash my clothes.? Later, he told his father: ?I cried for Mum for a long time and then I was quiet. I was waiting for the water to go and then I got down.?

Jillian Searle said she had already begun to grieve as they searched for Lachie in the aftermath of the wave.

?I was just so frantic for hours and the relief was just so strong,? she said. ?I couldn?t believe it and I still can?t believe he?s here.? The family returned to Perth on Wednesday still astounded that they had survived.