'We Are Going to Find Natalee'

June 10, 2005 — -- For 11 days, the family of Natalee Holloway has been on the island of Aruba searching for her day and night. The police and military have been combing the island, looking for any trace of the beautiful Alabama teen who came to the Caribbean island with her friends to celebrate their high school graduation.

"I know in my heart, and I know in my faith in God, we are going to find Natalee," Beth Twitty, Natalee's mother, told "20/20's" Deborah Roberts in an exclusive interview airing tonight at 10 p.m.

Giving up hope is "not an option," she told Roberts.

The 18-year-old was looking at a bright future, having won a full scholarship to college for pre-med. And her mother was extraordinarily proud of her daughter. "I was excited for her. What an accomplishment. What a huge milestone in her life -- to me the summer was a bridge to another life," she said.

Her father, Dave Holloway, who is divorced from Beth and lives in Mississippi, last saw his daughter at her graduation. "We hugged each other, and got some pictures and I asked her to be careful on her trip. And that was the last time I've seen her," he said.

The high school grads and their chaperones stayed at the Holiday Inn for their five-day trip. The trouble began after sunset on their final night.

Investigators are trying to piece together events that occurred after Natalee and her friends went to Carlos 'n Charlies', a local bar.

Did Natalee drink too much? Could she have run away?

Her father doesn't think Natalee would have run away. "She has too much going for her. She has a family, a close-knit family. That would not be, in my opinion, an option," he said.

What is known about the last hours before Natalee disappeared is sketchy, and police have kept a tight lid on details of their investigation.

Rumors have only added confusion to the case. What we do know is that Natalee was last seen getting into a car with three young Arubans her mom says befriended her during the trip.