From Ottawa comes the story of a runner who woke up in the hospital with a burning question: who saved his life?

Tommy Chan went for a five kilometer run on May 20th, but he doesn’t remember anything several days either side of that. All he knows is what the doctors told him: he suffered post-run cardiac arrest.

A bit of detective work revealed at least where he was when he collapsed: a running app called Strava told him he finished his 5K around Bronson and Carling at 7:50 p.m. A smartwatch that is attached to the app to track his heart rate has a telling lapse just after that time.

Paramedics, meanwhile, told him that they had responded to a call about a man suffering cardiac arrest near that location around one hour later. He had been resuscitated with a defibrillator, but not before bystander CPR was administered; deep bruising and a broken rib being two souvenirs of the kindness of strangers.

Rewinding to May 20th, and Tawnya Shimizu was on a walk with her daughter when she saw a commotion just next to her car. A man, it appeared, had collapsed.

“I could hear the 9-1-1 operator giving directions on CPR and counting out the timing,” she told CBC News Ottawa. “So my daughter was immediately like, ‘Mommy, you’re a nurse. You need to help!'”