The incident happened around 10 a.m. near the finish line. The runner, a man in his mid-50s, was without vital signs when he collapsed, according to Doug Waugh, deputy chief of operation with Hamilton Paramedic Service.
A number of doctors and nurses who were volunteering at the marathon performed CPR on the man, Waugh said.
"So he was treated immediately," he told CBC Hamilton.
He was transported to Hamilton General Hospital where he died, Waugh said.
More to come