“A 24-year-old runner named Rachel Appa, running her first New York City Marathon, collapsed near mile 24 and died hours later, and according to her father she died from rhabdomyolysis, a life-threatening condition in which damaged muscle tissue breaks down and releases toxins into the bloodstream.”

The underlying event is real and multiply sourced. A 24-year-old woman from Lewisberry, Pennsylvania, collapsed during the New York City Marathon on Sunday and later died at a hospital, according to New York police, and her family said she had rhabdomyolysis. Rachel Apa, 24, collapsed at Mile 24 near 85th Street in Central Park, a bystander administered CPR before medical staff took over and took her to a hospital where she died, according to New York Road Runners, and she was a Pennsylvania native and former Bucknell University field hockey player who wrote on LinkedIn that she was running to raise money for the Parkinson's Foundation in honor of her late grandfather, in her first marathon. The New York Police Department said emergency medical workers took her to Mount Sinai Hospital in critical condition around 2 p.m., where she died hours later, and New York Road Runners said medical staff then used a defibrillator. The cause of death is, at this point, a family attribution rather than an official finding. While the city's medical examiner has not yet determined a cause of death, Apa's father told The New York Times that the 24-year-old suffered the rare muscle condition rhabdomyolysis. The city medical examiner's office said Tuesday that it is still investigating. Her father, Steve Apa, said she died of rhabdomyolysis, a condition in which damaged muscle breaks down and releases its contents into the bloodstream faster than the kidneys can clear them, and he gave the family's account to the New York Times, which first reported her death. On the definition, clinical references describe the mechanism more precisely than the viral phrasing. Rhabdomyolysis is a clinical syndrome characterized by skeletal muscle breakdown and the release of intracellular components such as myoglobin, creatine phosphokinase, electrolytes, and sarcoplasmic proteins into the bloodstream, which can lead to systemic complications including acute kidney injury, electrolyte disturbances, and disseminated intravascular coagulation. It refers to the rapid breakdown of striated muscle followed by leakage of muscle fiber contents, including myoglobin protein and electrolytes, into the bloodstream, leading to acute renal failure and potentially death in severe cases. Acute kidney injury or acute renal failure is its most important complication, occurring in 13% to 50% of patients, due to renal vasoconstriction, intraluminal cast formation, and direct myoglobin toxicity. Context on rarity and on collapse during marathons: Deaths during marathons are extremely rare, experts say, even as more people run these grueling 26.2-mile races. A Mount Sinai nephrologist not involved in the case said rhabdomyolysis is rare but that he has seen cases at the New York City Marathon before, and that heat and humidity appeared to be the differentiating factor. Twenty-four runners were treated for rhabdomyolysis after the 2022 New York City Marathon, when temperatures peaked at 75 F with humidity near 80 percent. CNN also reported a cardiologist's view that the most common cause of sudden cardiac arrest in a marathon is myocardial infarction, not rhabdomyolysis, and that for younger runners the second most common cause of death from cardiac arrest is "unexplained," even after an exhaustive cardiac workup.