Patient One was 24 years old and pregnant with her third child when she was taken off life support.

It was 2014.

A couple of years earlier, she had been diagnosed with a disorder that caused an irregular heartbeat, and during her two previous pregnancies she had suffered seizures and faintings.

Four weeks into her third pregnancy, she collapsed on the floor of her home.

Her mother, who was with her, called 911.

By the time an ambulance arrived, Patient One had been unconscious for more than 10 minutes.

Paramedics found that her heart had stopped.

After being driven to a hospital where she couldn't be treated, Patient One was taken to the emergency department at the University of Michigan.

There, medical staff had to shock her chest three times with a defibrillator before they could restart her heart.

She was placed on an external ventilator and pacemaker, and transferred to the neurointensive care unit, where doctors monitored her brain activity.