''Krazy Kerris'' Browne felt fine when she crossed the finish line of the 102km Tarawera Ultra after nearly 20 hours' running. Shortly after, she collapsed and stopped breathing.
The well-known local runner, who formed the group Jogging the Power Poles to get beginners running, told the Rotorua Daily Post she felt prepared for Saturday's race.
"It was very hot out there; people got pulled out with kidney issues, dehydration," she said.
"But I knew it would be tough, so I hydrated very well going into it."
Around the 70km mark Mrs Browne changed her shoes and picked up the pace.