Their son died after his first day of football practice at Bucknell. They want answers.

The night before Calvin Dickey Jr.’s first and final football practice at Bucknell University, he slept in his parents’ hotel room.

Dickey, who everyone called CJ, had spent the summer lifting weights and running drills near his home in Tampa. Warm and dutiful, with a tendency to worry about right and wrong, Dickey had been recruited by Bucknell to be an offensive lineman, “another big man on the offensive side,” as the university put it on National Signing Day. Dickey aspired to play in the N.F.L., but as a hedge he also aimed to become a pharmacist.

On that first afternoon of football practice, Dickey, 6-foot-4 and 295 pounds, collapsed. His family rushed to meet him at the local hospital, certain he just needed to drink water and recover. Instead he rapidly became sicker and sicker: his kidneys failed, his calves and arms swelled until he needed surgery, and finally his heart gave out.

On July 12, two days after his first practice at Bucknell, Dickey died. It was a brutal reversal for an 18-year-old athlete who just days before appeared to be in his prime.

“We all stood around, just in shock,” Nicole Dickey, CJ’s mother, said, her voice breaking. “Two days. This big, healthy kid, that they had to put an extension on the bed because he was too tall for, is no longer here?”

Doctors told the Dickeys that their son died from rhabdomyolysis, or muscle breakdown, caused by exertional sickling. It’s a rare condition triggered by exercise that is too intense in someone with the sickle cell trait, a sickle cell gene inherited from just one parent. Such exercise can cause the body’s red blood cells to convert from their traditional round shape into hook-shaped sickles, blocking the bloodstream, preventing the flow of oxygen, and leading to organ failure. ESPN first reported on the presumed cause of Dickey’s death.

The Dickey family learned that CJ had sickle cell trait about two weeks before he arrived at Bucknell, because of NCAA-mandated testing.

From 2000 to 2010, sickle cell trait was the leading cause of death in college football, said Douglas Casa, a professor at the University of Connecticut and CEO of the Korey Stringer Institute who studies how to prevent death in sports. After the NCAA began requiring schools to test for the trait and to educate students and coaches, the rate of death associated with it among Division I football players dropped by nearly 90 percent, according to a report published in Sports Health Journal.

Since 2010, only seven college athletes have died from exertional sickling, the National Center for Catastrophic Sport Injury Research found.

The question that haunts the Dickeys, the one that wakes them up at night, throttling them and refusing to let go, is how did CJ become one of them?

Sickle cell disease is the medical name for a group of blood disorders that occur in people who inherited the sickle cell gene from both parents. Sickle cell trait, which CJ had, is different — it only means that someone inherited the sickle cell gene from one, but not both, of his parents. Eight percent of Black Americans have it, but it is not limited by race.

And it should not be a death sentence as long as an athlete stops exercising at the first sign of “sickling,” which can feel like the leg muscles being pressed or squeezed, sometimes accompanied by low back pain and more fatigue than usual.

“If someone stops right when they feel that, they could be fine 10 minutes later,” Casa said. He called athletes’ deaths from exertional sickling “100% preventable.”

It is not clear if CJ or his Bucknell coaches were educated about the signs to watch for, as the NCAA mandates, before that first practice. His parents don’t know if he tried to push himself past his limit, if the coaches urged him on or pulled him back, or if they even noticed anything was amiss.

Calvin and Nicole Dickey, CJ’s parents, say Bucknell has refused to provide any details about the practice that led to their son’s death, or the protocols the school did or did not have in place to prevent it. The autopsy report from the local coroner’s office is still pending, though a private autopsy commissioned by the family found sickled cells in CJ’s bloodstream, they said.

The Dickeys are now considering legal action against Bucknell.

In a statement, a Bucknell spokesman offered condolences and said he could not comment further because the school is “still awaiting critical information” in an ongoing investigation.

“We understand the gravity of the situation,” the spokesman said. “We are committed to sharing information with the Dickey family privately and respectfully as soon as it becomes available.”

For almost ten years, Nicole and Calvin Dickey wanted to have a child. They tried on their own, and then they did three rounds of IVF without conceiving. Finally, they adopted a girl. Three weeks later, Nicole found out she was pregnant with CJ — an unexpected godsend.

In the three months since CJ died, his parents have become detectives, trying to pinpoint the moment things went wrong. Nicole has spent hours online researching changes in altitude between Tampa and Lewisburg (which could have increased the risk of sickling) and studying the NCAA guidelines for sickle-cell trait.

“The only thing that we’ve received has been a lot of platitudes, a lot of ‘We’re sorry,’” Nicole said.

The NCAA mandates testing for sickle cell trait because of a legal settlement with another grieving family, that of Dale Lloyd II, a Rice University football player who died in 2006 from acute muscle breakdown associated with sickle cell trait.

“You can play intense sports with sickle cell trait,” said Dr. Randy Eichner, a retired professor of medicine and football team internist at the University of Oklahoma, adding that the school sent students with the trait to the NFL, where they did fine.

Transitional times, like the first day of practice after a break, tend to be the most dangerous. The NCAA recommends that schools slowly build up the intensity of their training, and allow for rest and recovery between intense bouts of exercise. (Athletes without sickle cell trait can also experience muscle breakdown, though it’s unlikely to be fatal. In September, for example, nine members of the Tufts men’s lacrosse team were hospitalized with rhabdomyolysis after a 45-minute workout led by a NAVY seal alum).

Coaches also should not use exercise or conditioning as punishment, according to a report on best practices that is endorsed by the National Athletic Training Association and other groups.

“You tell the athletes, if you feel these things, it’s not you being a wimp,” Casa said. “You can still do the same workout, it just might take a little more time.”

Nicole Dickey recalled speaking on the phone with Bucknell’s head football athletic trainer, Kaiti Hager, about Dickey’s positive test before he arrived for the season. It is not clear to her now if they had a plan in place to be alert to her son’s condition. But she didn’t think much of it at the time — CJ had excelled in high school baseball and football, and spent the summer conditioning at an elite football training academy in Tampa.

She sent CJ to his first day of practice with a folder full of medical information to share at a scheduled med check. She doesn’t know if that check took place, or what happened afterwards.

All that is clear is that just before 5 p.m., according to EMS audio recordings obtained by the Inquirer, emergency responders were called to Bucknell’s football practice field to treat a young man struggling to breath.

When the Dickeys raced to meet their son at the local hospital in Lewisburg, CJ was parched and still unable to fully catch his breath.

He said the team had been doing up-downs, an exercise that involves doing a push-up and jumping back up into a squat, because some kids weren’t doing the weight drills correctly, Nicole Dickey said. The Inquirer reached out to several players on Bucknell’s football team, but they did not respond to requests for comment.

A doctor handed the Dickeys a pamphlet about rhabdomyolysis, or muscle breakdown. CJ was displaying signs of “explosive rhabdo,” which so quickly ravages the large working muscles and “evokes an acute metabolic storm,” as Eichner described it, that it can kill in less than an hour.

Doctors told the family that CJ needed to be transferred to a nearby trauma center. Once there, over the next two days, he was put on dialysis and rushed into emergency surgery to relieve the pressure in his arms and legs, his parents said. On Friday evening, his heart stopped multiple times. After the fifth time, he could not be revived.

A month after CJ’s death, Nicole and Calvin Dickey received boxes from Bucknell of some of their son’s belongings: his clothes, his size 15 sneakers, his new bedding and school supplies — all the things they bought him to begin his new life as a college football player. They haven’t been able to bring themselves to fully unpack.

They say they cannot rest until Bucknell shares what happened, publicly, so that no other family has to go through what they have. Until then, all night they go in circles.

“It was very callous, in my opinion, as to what happened that day,” Calvin Dickey Sr. said.

Nicole interjected, “And then life continues—”

“And then they expect us to simply go on with life,” Calvin said, “and we have no idea what happened to our kid.”