NEW YORK — When Ali Truwit crossed the finish line of the Copenhagen Marathon in 2023, she had a clear plan for the next few years. She was about to graduate from Yale University, where she was part of the Division I swim team, had a consulting job set up at McKinsey & Company, and was set to travel to Turks and Caicos on a celebratory trip.

Ten days later on that vacation, the unthinkable happened.

She was snorkeling when a shark attacked her and bit off her left foot and part of her leg. On her 23rd birthday, she underwent surgery to amputate her leg below the knee. Running at all, let alone training for another marathon, felt like a far-away fantasy.

On that boat, one of the first responders, Matthew Bevilacqua, helped keep Truwit conscious. In a social media post, Truwit recounted that she joked, “At least I got my marathon in before this.” Without missing a beat, he responded: “You’ll run another one.”

He was right. Two-and-a-half years after that attack, the 25-year-old is lacing up her shoes for another marathon – this time, to run the TCS New York City Marathon on Nov. 2.