Mery Daniel, 31, shares that spirit. “I choose to focus on the positive,” she says. “I’m happy to be alive.” Of patients like Daniel, Spaulding’s Dr. David Crandell tells PEOPLE, “It’s been incredible to see their resilience.” After a trauma like this, Daniel, who is studying for the medical boards, says, “You look at people in a different way: what’s inside of them, what defines them.” She adds, “I didn’t have a decision to make about my leg. It was gone when I woke up. To be frank, it wasn’t that emotional. I mean, it hurt. But in the grand scheme of things, I was just happy to be alive. The doctor woke me after surgery and said, ‘You’re very lucky because your heart stopped twice.’”

Professional ballroom dancer Adrianne Haslet, 32, tells PEOPLE, “The fact that people truly believe I’m going to dance again has been a big deal. I’ve had studios from all over the country send pictures with little girls holding signs that say, ‘We believe in you, Adrianne!’ That makes me believe it, especially in the hard moments.”

Heather Abbott, 38, says, “When I was in the hospital, Aviva Drescher, one of the Real Housewives of New York, came to visit. She has a prosthetic leg, and it looked just like a real leg. It had veins and a birthmark. Seeing her and speaking to her helped me feel better about what kind of choices I have. It helped me see that some things in life wouldn’t have to change that much. That was a big deal.”

The lives of the 16 people who lost limbs that day were forever changed.

Among the most grievously hurt were Marc Fucarile, 34, of Stoneham, Mass., and Roseann Sdoia, 45, of Boston, who are featured in the issue and exclusive PEOPLE videos.

Stranded when the last available ambulances raced past them, the pair were thrown in the back of a police van to be rushed to the hospital.

As the vehicle hurtled through the streets of Boston, Fucarile, whose right leg was blown off, drifted in and out of consciousness. "I thought I was going to die," says the father of a son, Gavin, 5.

“Alycia is the mother of Avey, who is a beautiful, sweet, 3-year-old girl who also happens to have Leukemia. Imagine what that’s like for a parent. While you’re just figuring out how to take care of a baby, you’ve got to figure out how you’re going to pay for expensive treatment that could save your baby’s life.

Any parent knows that there is nothing we won’t do to take care of our kids. And it’s nice to have somebody getting your back. And that’s why the Affordable Care Act made it illegal for bad actors in the insurance industry to discriminate against kids like Avey. And today, Avey is doing just great. She was here just a second ago, where is she? There’s Avey — hey, sweetie! So Alycia wrote in — she said, “The health care law is about people like me. It’s AlyciaCare.”

Ending Insurance Company Abuses: Thanks to the Affordable Care Act, insurers can no longer put a lifetime cap on how much care they will pay for if you get sick or cancel your coverage when you make a mistake on your paperwork. Starting in 2014, health insurers will be prohibited from charging you more because you are a woman.

Coverage for Pre-existing Conditions: If you have been uninsured for six months and can’t buy private insurance because of a pre-existing condition, you can join the Pre-existing Condition Insurance Plan. And under the new law, no plan can deny coverage to people under age 19 because of a pre-existing condition. Starting in 2014, health insurers will be prohibited from discriminating against anyone due to pre-existing conditions.

Cheaper Prescription Drugs: If you’re in the donut hole, you will receive a 50 percent discount when buying brand-name prescription drugs covered by Medicare Part D. The discount is applied automatically when you fill your prescription—you don’t have to do anything to get it. These changes are already saving seniors billions of dollars. And by 2020, the donut hole will be closed.