She was in a grueling 340-mile race. Then came a highway, and a truck.

Kim McCoy remembers the porch of the Alabama church where, exhausted from running all day, she grabbed an hour or so of sleep before dawn on that late June day.

It was the day she should have died.

There were dead bugs everywhere on that porch, but there was also a decent, open bathroom with carpeting at the church, a luxury for someone nearly 270 miles and five days into a 340-mile ultramarathon across the Deep South. Sleep came easy. Then dawn approached, and it was time to hunt down breakfast at a nearby gas station and begin the final, 70-mile push to the finish.

She remembers little else from her run that morning. What she next remembers is waking up in a hospital bed and seeing four intravenous lines emerging from her arm. As a labor and delivery nurse at NewYork-Presbyterian Hospital, she knew four IVs were a bad sign.

"I think I knew at that point that I had lost my leg," McCoy, 37, said in a recent interview.

She does not remember the impact with the SUV that sent her flying more than 100 feet down the four-lane highway in northern Alabama, about 30 miles southeast of Huntsville.

Thomas Grinovich does. A fellow participant in the race, he was trying to cross Highway 72 with McCoy. One moment, he said, McCoy was close to his left shoulder, halfway across the dark, wide roadway. The next, a headlight, the roar of an engine, then a horrific, pounding thud.

"When I get the flashbacks," he said, "that sound is what I hear."

On June 18, McCoy and Grinovich were among the 66 runners who set off from West Memphis, Arkansas, for the inaugural running of the Heart of the South Road Race, the brainchild of Gary Cantrell, known in the ultrarunning world as Lazarus Lake.

Since the mid-1980s, Cantrell, a bearded, Camel-smoking ultrarunner from Tennessee, has been creating some of the world's toughest events. His competitions are more journeys than races, ones many runners never finish. In the past three decades, only 15 people have completed Cantrell's Barkley Marathons, a 100-mile venture over unmarked terrain in the Cumberland Mountains in eastern Tennessee.

As ultrarunning - any race longer than a 26.2-mile marathon - has become more popular, the sport's hard-core practitioners have pushed the limits of the sport and human endurance. Races that stretch more than 200 miles over several days are no longer uncommon.

Catastrophic injuries and collisions with cars are rare in ultrarunning, although the sensation of dodging death - from exposure, exhaustion, dehydration or even an encounter with a bear, a mountain lion, a rattlesnake or speeding traffic - can be a part of the appeal. But McCoy's accident, crossing a highway after five endless days of running, raises the question of whether this race was a test of rigor or recklessness.

Cantrell created the Heart of the South Road Race because he felt his signature event, the Vol State race across Tennessee, a 300-mile journey from Missouri to Georgia, had become too easy, with spectators along the familiar course offering runners nourishment and places to rest.

Heart of the South runners, who had to acquire food and water along the way and carry those items in lightweight backpacks along with extra clothes and a small blanket, didn't get a map or warnings about the route from West Memphis to Castle Rock, Georgia, until hours before the race.

In a recent interview, Cantrell said he spent months thinking about, designing and researching the route, searching for roads that met his safety standards, had plenty of opportunities for food and water, and included some history. He had set up the course to roughly follow the Lee Highway - Highway 72, in that region - and to honor DeWayne Satterfield, an elite ultrarunner from Huntsville who died of cancer at 55 in March.

He did not seek permits for the race, which in some states can require race organizers to install warning signs at hazardous crossings, because, he said, pedestrians are allowed on all the roads, including at that T-intersection on Highway 72 without any traffic signals.

Gary Cantrell, the mastermind behind the Barkley Marathons, at home in Bell Buckle, Tenn., on Aug. 12, 2020. Cantrell organized and designed the Heart of the South Road Race, the 340 miles race where Kim McCoy lost her leg after being hit by a vehicle on the course that he studied and considered safe. (Houston Cofield/The New York Times)

Cantrell said there was a stretch that was "really bad," on the busy roads west of Huntsville, but the crossing where McCoy was hit was not on that bad stretch.

Candice Burt, an organizer of ultramarathons, including the Tahoe 200 Endurance Run around Lake Tahoe, which crosses major highways but uses signs required by the permits she gets, said that after several days without sleep, runners can lose the ability to gauge how quickly a car might be approaching.

"As race directors, we need to make races scenic and challenging but also safe," Burt said.

Cantrell had studied his options. The intersection of New Hope Cedar Point Road and Highway 72 seemed safe enough, he said, offering decent sight lines in either direction and a grass median.

"We said this should be no problem," he said.

Why She Runs

Kim McCoy has reddish-brown hair, bright eyes and a smile that eases the pain of labor for women under her care. Before the Heart of the South, she was running 3 to 10 miles after her 12-hour nursing shifts and as many as 30 miles on her days off. Speed matters little to her. She has run marathons in a tutu and in a fox costume. If she sees a pretty bed of flowers on a run, she stops to look.

She did not run much growing up in Riverside, Iowa. She was in the school band (baritone saxophone) and choir in high school. She tried cross-country in her senior year.

"I got lost in my first race," she said.

Then she got a stress fracture, and that was that.

McCoy ran recreationally at the University of Iowa and kept it up when she moved to New York in 2006. She tried a half-marathon in Central Park, then marathons, and before long she was running the Great New York 100 Mile Running Exposition and other ultramarathons throughout the country.

She was drawn to the Heart of the South race because she liked the organic feel of a multiday race with no support. She would carry her phone, some cash, a credit card, some snacks and supplies, and figure out along the way where the next bottle of water was going to come from.

With 90 miles to go, the pounding of a half-million steps and the heat of the asphalt had melted the sole of her left shoe. She could feel the hot pavement on her foot. She taped some rubber from a tire she found to it. It didn't work. She stopped at a Walmart to buy new shoes, but they were too narrow.

No big deal, she thought. It was only another 90 miles. She had managed the race perfectly. During the 95-degree days she had taken it easy, even grabbing the occasional 30-minute nap. In the evenings and at night, when it was cooler, she pushed. She felt great. Settling in for rest on that bug-infested church porch, she could feel the finish.

'I Didn't Like the Looks of It'

Ray Krolewicz got to the Highway 72 crossing about 1 mile ahead of McCoy and Grinovich. For more than five days they had been leapfrogging one another and texting about places to eat or use a bathroom or get water. They all knew about a gas station with breakfast sandwiches about 2 miles past the intersection.

A veteran ultramarathoner, Krolewicz, 65, is used to running along rural highways as cars blow by him at crazy speeds. It was still plenty dark when he got to the Highway 72 crossing. No flashing lights. No warning signs about a race. Just a big road with cars and trucks flying past at 70 mph.

"I didn't like the looks of it at all," he said.

Soon, McCoy and Grinovich were making their way toward the highway. They had endured a long stretch without much food the previous evening. During one break, Grinovich had tried to get someone to deliver pizza to the middle of nowhere, offering a $20 tip. No luck.

Later, on the way to the church, they shared some snacks, an avocado and some nuts. Then, at the church, they went to sleep. They woke about an hour later and headed up the road refreshed and ready for more food.

"The goal was to finish in under seven days, and we were right on the edge of that," Grinovich said.

"We're going to have to be real careful here," he thought as they looked at the Highway 72 crossing. Go halfway. Stop on the median. Wait for a break. Dash to the other side.

They made it to the median, then thought they saw an opening. Halfway across, Grinovich saw a flash of light and pulled back. McCoy kept going. He heard a crack and was sure she was dead. Then he ran to her and heard a moan. Somehow, after being sent airborne down the highway, she had hit feet first and rolled, rather than crashing on her head. As she tumbled, her backpack had cushioned the impact.

Trying to drag her off the road, he heard the exposed bone of her damaged leg grinding on the pavement. Two cars whizzed by, somehow avoiding them. He waved his arms at an approaching truck, praying the driver would see them. The truck slowed, then turned and blocked the highway to stop traffic.

Grinovich saw the blood pooling beneath McCoy. He grabbed a shirt and tied a tourniquet around her right thigh.

Down the road, Krolewicz heard a siren. An ambulance was speeding past him.

"There's been so many thousands of times people have done these things," Cantrell said of his races. "Eventually the number comes up."

'I Need Running in My Life'

McCoy ended up at Huntsville Hospital, where doctors amputated her right leg just above the knee and treated multiple fractures in her arm. She received roughly 5 pints of blood and 4 pints of plasma. The average adult has 8 to 12 pints.

On July 1, she traveled back to New York on a special plane that NewYork-Presbyterian provided. Her rehabilitation soon presented its own complications.

She lived with her sister, Jessica, in a third-floor walk-up in northern Manhattan. She could not use crutches. Her surgically repaired broken arm could not bear her weight. This month, she moved to a ground-floor apartment in Harlem. For now, she is using a wheelchair and a walker, and working on her balance.

Who bears responsibility for McCoy's accident is a question that lawyers and insurance companies may have to decide.

She has not filed a lawsuit but has retained a lawyer, even though she signed a waiver releasing Cantrell from liability before the race. Waivers don't allow race organizers to act with negligence, the definition of which can be subjective.

"We were just trying to make it across the road," she said.

When the swelling goes down, technicians will fit her right leg for two prosthetics: one for walking and, eventually, a blade for running.

"I need running in my life," she said.

She wants to run ultramarathons again.