A terrorist attack cost this Paralympian her legs. But it also taught survival instincts that have made her an elite competitor.

• Beatrice de Lavalette is a French para-equestrian who will compete in the Tokyo Paralympics.
• De Lavalette was severely injured in the 2016 Brussels bombings, which caused her to lose her legs.
• De Lavalette was riding five months after the bombing, which instilled competitive resilience in her.

Thirty-five people died in the 2016 Brussels Airport terrorist bombings. Beatrice de Lavalette was almost the 36th.

The 23-year-old French-American horse rider, who is set to compete at the Paralympics in Tokyo as a dressage equestrian later this month, is the most critically injured survivor of the attack today. De Lavalette was just 17 years old at the time and was on her way to visit her parents in Florida to help set up their new house, but she never made it past the checkpoint.

She was in the baggage drop-off line when the explosion went off.

"I remember thinking, 'You have got to be kidding me, this really just happened,'" de Lavalette told Insider. "I was bleeding out, so I was going in and out of consciousness, but before I fully lost consciousness, I remember looking around and seeing flames, ash, and a dark room. But I remember seeing the door to the outside because it was basically the light at the end of the tunnel, and I knew if I got past that point, I would be okay."

-Anna Ahronheim (@AAhronheim) March 22, 2016

But when first responders came to triage and rescue survivors, de Lavalette was tagged red, meaning they deemed her highly unlikely to survive. The first responders were instructed to prioritize victims who were more likely to survive, leaving de Lavalette a non-priority.

De Lavalette laid on the ground, watching paramedics and firefighters rescue the other survivors around her. She would have been left to die had she not taken matters into her own hands.

"I remember thinking, 'what about me, I'm here too?'" she said. "I remember thinking I should probably be doing something, so I started screaming for help in French and English, and I saw a fireman who was putting out the flames, so I threw my hand straight up in the air, and he saw me."

De Lavalette had to prove that she was capable of surviving just to be rescued.

It was not only a moment in which she saved her own life, but it was also her springboard for the recovery process it would take to overcome the life-changing event, return to her sport, and make a run to Tokyo this year.

"That moment taught me that, no matter what, I need to fight for what I wanted," de Lavalette said. "It gave me a perspective of a combatant ... I'm using that word because it's very similar to the French word 'combattante,' which means someone who's fighting through something, but they're surviving."

De Lavalette fought physical and mental barriers to return to her sport

De Lavalette was in a medically induced coma for the first month after the attack.

She woke up in May 2016 to learn that she had suffered internal injuries, second- and third-degree burns, a spinal cord injury, and the amputation of both legs.

"The first four months were in the ICU, and then a month inpatient rehab," de Lavalette said. "I had a lot of ups and downs of emotion, depression going up and down, and days that I was not able to move, and some days where I was like 'let's get this, I'm good to go.' But a lot of it was difficult to deal with."

A post shared by Beatrice De Lavalette (@beatriceldl)

De Lavalette grew up playing soccer and doing track in addition to horse riding, but playing those two sports were gone from her life at that point. But horse riding was still possible for de Lavalette, and a short and simple phrase that was echoed by her family members while she was on her hospital bed fueled her return to the sport.

"Anything is possible," de Lavalette said. "It was something my parents and my family and my friends told me in the hospital, that anything is possible, your here for a reason, and you survived ... It kept me from crying every day, and it worked."

Within five months of the incident, de Lavalette got back on a horse and started to practice equestrian dressage again. After the attack, the first horse she mounted was a Spanish horse named Didi, who de Lavalette knew before the attack but never rode competitively.

But Didi ultimately ended up being the horse that allowed de Lavalette to make her para-equestrian debut at a show in April 2017. After two more years as a para-equestrian, de Lavalette qualified for the Tokyo Paralympics to compete for Team USA, and she will be riding a Dutch horse named Clark.

De Lavalette's goal is to make it to the medal podium so she can remind her followers and the rest of the world: "anything is possible."