Runner, 24, texted her father 'Ow ow' before collapsing and dying two miles from the New York Marathon finish

Rachel Apa, a 24-year-old field hockey player from Lewisberry, Pennsylvania, was running her first marathon to raise money for Parkinson's research in tribute to her late grandfather when she collapsed at mile 24, near 85th Street in Central Park, at around 1:30pm on Sunday. She died in hospital that night from rhabdomyolysis — a rare condition in which muscle cells break down and release toxins into the bloodstream, which can be triggered by extreme physical exertion even in healthy athletes. Her mother Michelle had seen her pass at mile 14, smiling and high-fiving spectators, before making her way to the finish line to wait.

Bystander Michaela Nicholas, whose fiancé called for help, held Apa's hand while members of the crowd took turns performing CPR until race medics reached the scene.

Apa had written of her grandfather: 'He taught me to stay active, push my limits, and embrace challenges.'

New York Road Runners said they are 'deeply saddened' by her passing; the city medical examiner has not yet issued a formal cause of death.