Tiffany Stoker and Tylinn Tilley credit their friendship with helping to keep them alive.

“If we would have let fear overtake us, we would have never been able to get out,” Tiffany said.

The Utah girls, both 13, survived a deadly boating accident that claimed four lives after they swam for hours, singing songs and shouting prayers as they fought exhaustion in the 53-degree waters of Bear Lake.

The teens were on a ski boat with family friends Lance Capener, his wife Kathy, their two daughters and another friend from school. The weather took a turn for the worse, bringing 76-mph winds and 10-foot waves.

The boat capsized, throwing all seven people into the water. All on board were wearing life jackets, but the waves separated Tiffany and Tylinn from the group. The two tried to swim the 6 miles to shore, treading water for hours.

They chanted songs and said prayers, even massaging each others' cramps.

Rescue workers found the two girls bobbing in the water, both suffering from hypothermia. The only other survivor was Kathy Capener.

The friends remain bonded by their survival amid the tragedy.

“It’s nice to have those friends who were really encouraging. If she was doubting the whole time, I don’t think any one of us would have been able to make it,” Tylinn said.

Added Tiffany: “We’re unbreakable.”

Mother of three, Katheryn Capener, also survived and is currently being treated at a local hospital. Her husband, Dr. Lance Capener, their two daughters, 13-year old, Kelsey and 7-year old, Kiley, as well as 13-year old, Sierra Hadley, did not survive. Funeral services are being scheduled for next week.

If you would like to find out more about the families, you can visit their websites.

The Capener Family http://www.anythingforafriend.com/index.php?cID=290

Sierra Hadley http://www.gofundme.com/w35d8gy8?fb_action_ids=10206160484638531&fb_action_types=og.shares

The Associated Press contributed to this report.