By Emma Batha

LONDON (Thomson Reuters Foundation) - Last year Syrian refugee Yusra Mardini had to swim for her life when her boat broke down as she tried to reach Europe; this month the teenager will be swimming in the Rio Olympics.

Yusra, who is a member of the first ever Olympic refugee team, told how she and her sister Sara feared they might drown after their overloaded dinghy started taking in water as they crossed the Mediterranean to Greece.

Along with another refugee they jumped in the sea and pulled the boat for three hours through the water, saving the lives of 19 others.

"When I was in the water there was fear. You don't know whether you are going to live or die," the 18-year-old said in a video interview published by the International Organization for Migration (IOM).

Mardini, who will compete in the 100-metre freestyle, is among 10 athletes in the refugee team which will march behind the Olympic flag at Friday's opening ceremony in Brazil.

"When I was swimming for my life, I never would have believed I would be where I am now," the IOM quoted her as saying.

The two sisters, who now live in Germany, left their home in Syria's war-battered capital Damascus a year ago and headed to Turkey.

One evening they boarded a dinghy on the Turkish coast along with 20 others - around three times as many people as it was designed to carry.

"Before you go on the boat, people tell you that you are going to die," Sara told IOM in an interview published on Monday.

"So the first thing you think about when you get on that boat is death. You don't think of anything else."

Hundreds have died crossing the Mediterranean from Turkey as they tried to reach Europe after fleeing conflicts and political turmoil in the Middle East and elsewhere.

COLD AND EXHAUSTED

Sara, also a swimmer, said she told her sister that if their boat capsized during the journey they should just try to save themselves as it would be impossible to help everyone else.

But when the engine stopped and the boat started deflating she realized she could not let the others drown.

"We needed to have less weight on the boat and nobody else besides us could swim ... When I first got into the water my whole body was shaking like it does just before competition," she said.

"At that very moment I felt that life was bigger than me alone. All the people on that boat were part of me.

"I thought it was my duty to jump in the water ... if I (had left) them I would feel bad with myself for the rest of my life."

She described how her father's friend cut off her trouser legs in the sea to stop her clothing weighing her down.

After two hours she was battling exhaustion and knew she risked falling asleep and drowning.

"It was getting dark and cold, the wind was blowing and I was freezing. I could not open my eyes any more, they were full of salt water," she said.

They eventually arrived on one of the Greek islands in the middle of the night.

Her sister Yusra says she hopes her story will inspire others.

"Now we are training really hard," she said. "I think about making my parents proud and everyone who supported me."

The teenager has three dreams. "I hope that they will open the borders for refugees, and I hope to get a medal in the Olympics, and that my home town is in peace again."

(Editing by Ros Russell; Please credit the Thomson Reuters Foundation, the charitable arm of Thomson Reuters, which covers humanitarian news, women's rights, trafficking, corruption and climate change. Visit news.trust.org to see more stories.)