When the first bomb went off at the Boston Marathon last year, John Odom and his wife, Karen, were standing on Boylston St. The Odoms were visiting from California, waiting to cheer on their daughter, but they never got the chance.
"There was this huge explosion. The thrust came from our left and it was very hot and it just knocked you down to the ground," John said. "And right away I could feel there was something wrong."
He immediately knew it was a bomb, reports CBS News correspondent Elaine Quijano. Shrapnel had torn through arteries and veins in his leg. His wife Karen tried desperately to help him.
"I knew we were in terrible trouble, that he was losing too much blood," Karen said. "And our son-in-law appeared at my shoulder, taking his belt off and secured it on John's leg because he would have bled out right there on the street."
"I believed at that point in time that that was where I was going to die. Right there," John said. "And I was okay with that if that was my time to go."
His family, however, begged him to stay awake. The last thing John remembers is being carried to the ambulance.
Thousands of Boston's doctors and nurses rushed to hospitals around the city and waited for the injured to arrive. Among them was vascular surgeon Jeffrey Kalish at Boston Medical Center.
"To be totally honest, when I first walked in and first essentially saw John, he had actually arrested, which means his heart had stopped," Kalish said. "He was for all intents and purposes dead for a very split second."
After the surgery, Kalish told the Odom family to take things hour by hour.
"I told her that I didn't know if he was going to die, but I could not promise her at that point that he was going to make it out of the hospital," he said.
"It was that critical for several days, and he was on life support for two weeks," Karen said. "He had 11 surgeries in 28 days and it was a rough time."
The force of the blast had injured Odom's brain, but eventually he recovered enough to begin his grueling physical therapy at Spaulding Rehabilitation Hospital. On the first day his physical therapist, Jessica Guilbert, asked him about his goals.
"I said my goals are to walk, to be able to dance with my wife and to play golf," John said. "I had to learn how to go to the bathroom, brush my teeth, comb my hair."
Doctors weren't sure if John would ever walk again, but Guilbert encouraged him to believe he could.
"I didn't know if I thought I really could until Jessie took me down to the parallel bars and said, 'John, let's stand up,'" John said. "I knew at that point in time I was going to walk. And there was nothing that's going to stop me now."
John did walk out of that hospital - the last of the Boston bombing patients to go home. Recently, he even checked off one of his other goals: to dance once again with the high school sweetheart he married nearly 50 years ago and the woman who stood by his side for nearly five months of treatment.
John said the occasion was joyful for him.
"I couldn't take my eyes off of her when we were dancing," he said.
Last week, the Odoms returned to the hospital where Dr. Kalish saved John's life.
"I personally can't think of a more grave injury with the highest chances of dying at so many points along the way and such an incredible outcome," Kalish said. "He definitely ranks as a patient and a situation I will never forget."
John and Karen are in Boston for the one-year anniversary, reuniting with friends, family and the people who helped John through his recovery. They will be watching the marathon Monday, cheering on the runners including Guilbert, the physical therapist who taught John how to walk again.