A woman drove on icy roads in an area not familiar to her, she skidded across three lanes and fell into an icy pond where she was trapped for 18 hours. While her car could not be viewed from the road, a cyclist did spot her the next morning. Yes, people in Minnesota do cycle year-round.
Later she said that her cell phone fell into the water and quit working. She had tried calling OnStar, the emergency vehicle service, but just as someone answered, the battery in the car went dead and the call broke off. http://www.startribune.com/186844802.html
I have never used OnStar but I wonder: even if the connection broke off, wasn't the initial call enough to identify the caller and the location?
Oh, and just after the bridge collapsed over the Mississippi in 2007, I checked that my "Life Hammer" - that breaks window and cuts seat belts - is still in the car.