Runner, 24, texted her father 'ow, ow' before she collapsed and died two miles from the New York Marathon finish

Rachel Apa, 24, who had played field hockey at Bucknell University, collapsed at mile 24 of the New York City Marathon on Sunday and died — the event was her first — after developing rhabdomyolysis, a rare condition where muscle breakdown floods the bloodstream with toxic chemicals that overwhelm the kidneys. She had entered the race to raise money for the Parkinson's Foundation in honour of her grandfather, who died of the disease. Bystanders held her hand and performed CPR while medical staff rushed to her in Central Park.

Her father Steve called it 'unfathomable — perfect health, perfect shape, 24 years old.'

Rhabdomyolysis can strike even elite athletes, with early warning signs — swelling, weakness, dark urine — easy to dismiss.

Rachel's mum Michelle had watched her smiling and giving high-fives at mile 14, then headed to the finish line expecting to meet her there.