So recently there was a news article about how an Apple watch saved a biker. The biker was on a ride in Washington when he flipped his bike. He landed head-first on the pavement and was rendered unconscious. His Apple watch sensed the impact and called 911.
His son was waiting for him and received a text from the watch to notify him it detected a hard fall and sent a map with his location. By the time he got there, his dad was already gone and on his way to the hospital. His son received the message because he was listed as an emergency contact on the phone.