DAYTONA BEACH, Fla. -- The medical team had no idea where to even find injured driver Alex Zanardi as they raced toward the scene of his crash at the EuroSpeedway Lausitz in Klettwitz, Germany. The debris field stretched out for hundreds of yards on the grey pavement and the carnage looked like a war scene straight out of the movies.

Dr. Terry Trammell hopped out of the safety vehicle and tried running toward Zanardi but immediately slipped and fell. He assumed he slid in oil and was stunned to see it was actually Zanardi's blood pouring down the banking in a pool so slick Trammell had to crawl on his knees to the injured driver.

"We didn't know what had happened, if it was an accident, a bomb -- it could have been a bomb blast for all we knew," Trammell said.

It was four days after the Sept. 11 terrorist attacks 4,000 miles away in the United States. The CART Series was racing because the teams were stranded in Europe, there was no way to get back to the U.S. and racing as scheduled had been an emotionally draining decision. There was concern the series could be targeted, but the German host committee said it was safe to race.

Now, in the waning laps, one of the most popular drivers in motorsports had spun out exiting pit road and his car was hit straight on by another driver.

Trammell remembers an eerie silence as he waded through blood and car parts to get to Zanardi's sheared cockpit.

"I got there, I asked, 'Where are Alex's legs?"' said Trammell. "Your mind says one thing and the eye says something else. You are looking and something just wasn't right. His legs were not there, it was almost in slow motion and it was deathly quiet. It was perfectly clear, no sound at all."

Both legs had been severed above the knee and were blown to pieces all over the track. Zanardi was bleeding to death and Trammell and CART's renowned safety team had just minutes to act and get the two-time series champion into a helicopter and on his way to a trauma unit in Berlin.

Open-wheel racing is inherently one of the more dangerous disciplines and the drivers in the field have suffered their share of loss over the years. Greg Moore, a rising superstar, had been killed two years earlier in a crash in California and many still mourned the beloved Canadian. Now they saw another horrific crash scene, the safety crew's frenetic pace and there was silence on their radios.

The drivers begged for updates.

"I was told that he was gone. I was told wrongly," said former teammate Jimmy Vasser. "Tony Kanaan and I believed he had died for a very short period of time."

Zanardi went into cardiac arrest on the helicopter ride to Berlin and spent days in a medically induced coma. He was 34, one of the top drivers in the world, and awoke without either of his legs. He immediately turned toward rebuilding his life and in the 17 years since has become a world-renowned hand cyclist and Paralympic gold medallist . His next challenge is the Rolex 24 at Daytona, a twice-round-the-clock endurance race in which Zanardi will compete without his prosthetic legs and use a steering wheel designed for him to compete using only hand levers.

Zanardi's accident led to the creation for safety teams a kit of medical supplies to be used in traumatic injuries. Known as the "Zanardi Kit," it was on the truck when safety workers stopped James Hinchcliffe from bleeding to death from a punctured artery in a crash at Indianapolis Motor Speedway in 2015.

There are four drivers in the Rolex field who raced that day in Germany alongside Zanardi, while Vasser is at the Rolex as a first-year team owner and Paul Tracy is part of the NBC Sports broadcast. Trammell to this day is a medical consultant for the series that is now called IndyCar.

All shared their most vivid memories of that race with The Associated Press leading into Zanardi's return to North American racing:

HELIO CASTRONEVES

"That was a tough one because of 9-11, it was a dark moment for all of us. We couldn't get back to our families and racing wasn't very important. There was just a dark cloud, everyone was feeling terrible and no one wanted to race. But once the green dropped, we all focused and the track was very difficult. As soon as I heard 'Yellow' and I passed through the accident and I saw Alex's car and I think he was Tony (Kanaan's) teammate so I was curious who it was and I really looked at the car to see who it was and obviously I didn't see the front half of the car. It was terrifying. I could see pieces of the body lying on the ground, part of his legs. At that time I did not know what it was, I saw a lot of debris, but I realized it was something that was not right. Later on I realized what I saw."

SCOTT DIXON

"The biggest thing for me was the next day, the front page of the newspaper and the picture in which you could just see everything. I mean, his shoe in the air, body parts everywhere and I don't think in most countries you would be allowed to print that picture. I was young and I had not seen too much of that stuff before, so I didn't understand what it meant. It was my first year and I had never seen anything of that magnitude."

CHRISTIAN FITTIPALDI

"I saw the whole situation from the apron. Zanardi was so serious, so serious. (Alex) Tagliani had stuffed his car on Zanardi, and it ended up rolling another 200 metres. There was no one there. Probably the whole safety crew was on top of Zanardi's car. And I remember seeing some blood. I remember seeing only up to his rear view mirror. ... Yeah, we're out there to put on a show. We're all professionals, but at the same time to have fun. We're not going to war. It seemed in a way that we were going to war. It makes you think on a bunch of different things, is it really worth it? Should I really be doing this?"

TOWNSEND BELL

"It was my first ever IndyCar race. I was drinking through a fire hose just driving, let alone landing in Europe on 9-11. As I recall, I was the first car to come across his accident under yellow. It was just a tough, tough week. I have so many strong memories: there's Alex's accident, there's 9-11, but then I had one of my best races in my first-ever race. Exhausting, exhilarating, devastating all in one. I don't think I've ever had a race weekend like that since."

PAUL TRACY

"The weirdest thing was I was standing out on pit lane and everyone had disappeared. I thought, 'Where is everyone? Did I get left at the track by myself?' So I went into one of the offices and literally everyone was standing around watching a TV. A plane had gone into the first tower and like three minutes after I got there, the second plane hit. It was just mass confusion there over whether we would practice or race, we spent an entire day waiting and doing nothing as the series checked on the safety. There was a bunch of hoops that had to be jumped through before we had any clearance. Race day, I don't particularly remember, I didn't have a good car. Then I came around Turn 1 and there were parts everywhere on the track and I thought, 'Oh Jesus, this is not good.' It took a long time before anyone knew anything and everyone was fearing the worst because just by looking, you could see how bad it was."

DR. TERRY TRAMMELL

"I was able to create a compression dressing on the right leg out of his firesuit and managed that for a tourniquet and used the belt to tourniquet the left stump but I couldn't keep it on. It was like trying to put a band on a funnel. We just had to get him to the helicopter. We got to Berlin, and somewhere in all of that, someone handed me a plastic bag and said, 'You asked for this.' I was like, 'I did?' Well, it was his legs. It was all the pieces. The bag was X-rayed and then it went to the morgue. That was the first time the enormity of it all hit me, when I saw all the pieces in the bag, the body pieces that were not part of him anymore."

JIMMY VASSER

"We were there in Berlin, and he didn't wake up, and we had to go racing. We went to England and raced and then I went back to Berlin, and he had woken up by then. I got there and he had just gotten out of the shower, his first shower, and he's blow-drying his hair. Combing it, blow-drying it, and I thought 'That's how his hair is so feathered?' It was less than 10 days after the accident and I had gone there to be there for him, but I realized he was there for me. From that day I walked in and he was drying his hair, it was about my healing, not his healing."