By Jacqueline Sit, NEWS 9

OKLAHOMA CITY -- There were times Amy Petty thought she wouldn't make it through her rigorous training for the Oklahoma City Memorial Marathon, but 15 years ago she also didn't know if should would make it after being trapped under rubble in the remains of the Alfred P. Murrah Federal Building.

"There were times after the bombing that I felt I couldn't go on," she said. "There are times when I did the training and thought I can't do this, but you know somehow you just do. We're Oklahomans. We just pull ourselves up by our bootstraps."

Amy Petty was on the third floor of the federal building working on what started as an ordinary spring day 15 years ago.

"I heard this incredible roaring and people screaming and this lady screaming 'Jesus help me,'" she said. "Then I realized that was me, and I felt this powerful rushing sensation like I was falling to the ground and I was actually falling three floors with the building."

Petty was buried under several feet of rubble and couldn't see anything.

"I didn't know if I was dead or alive actually and just laid there until I heard men looking for the daycare babies," she said. "That's when I was able to scream and have them come and find me."

For years Petty bounced between despair and survivor guilt while she struggled to heal physically and emotionally.

"I had a lot of difficulty with my best friend," she said. "She had a 2 and 3-year-old baby girl and at that time I didn't have any children and it was hard for me to know that I made it and I lived when she had two babies at home and she was killed."

Petty said she felt like she got a second chance at life and she was determined to make her second chance a healthier one. After weight loss surgery she started running, biking and most importantly enjoying her family and her son Austin.

"I didn't want to have regrets again like I did when I thought I was going to die," she said.

Now 180 pounds lighter, Petty says when she hits the pavement in the Memorial Marathon she will be celebrating her second chance at life and honoring those who died.

"It has been emotional bringing back memories of those that we lost," she said. "We lost 18 and I knew the 100 or so people in our building that were killed."

The Oklahoma City Memorial Marathon is Saturday, April 25. In its tenth year, the marathon raises money to support the mission of the Oklahoma City National Memorial.

Fifteen Years: A Living Timeline
The bombing of Oklahoma City's Alfred P. Murrah Federal Building changed our city and nation forever. Experience the events of April 19, 1995, and the fifteen years since that fateful day. >>View the Timeline