I remember quite a few years ago, my buddy's girlfriend was 17. They had been together for years and he was planning on giving her a ring for her 18th B-day which was only a few weeks away.
We were at the local swimming hole goofing off and he and I walked back to the truck for a smoke. We were gone all of 5 minutes.
When we came back, she was floating face down. I tried CPR but she died at the hospital. Massive heart attack.