Lester Holt

He answered, perfect timing, creatine, smiley face.

These are hospital security camera pictures that show Autumn throughout the day and leaving work late that night.

Ten minutes later, she was home.

And minutes after that, her husband, Bob Verante, was on the phone to 911.

His wife slumped on the kitchen floor, gasping for breath.

The dispatcher asked the husband what he was seeing.

I think my wife is having a stroke.

Paramedic Steve Mason and his partner arrived at the Ferrante home to find a woman in very bad shape.

An hour after walking home from the medical center where she worked, Dr. Autumn Klein, seen here in hospital surveillance footage, was back as a gravely ill patient in its emergency room.

And whatever was happening to her was a medical mystery to the team trying to keep her alive.

Then they saw the blood, so neon red, so out of their experience.

When we come back, Autumn is surrounded by some of the best doctors in the country.

But no doctor can work miracles.

To them, this was out of this world.

Just couldn't make any sense out of it.

Maybe someone else could.

Dr. Autumn Klein had been rushed by ambulance to the ER of the University of Pittsburgh Medical Center after slumping to the kitchen floor of her home.

Now the trauma team surrounding her was trying desperately to keep her vital signs going.

Alan Jennings, at the time a reporter with NBC's Pittsburgh affiliate WPXI, covered the story.

He recounted what doctors later said about that night.