Yes they do occur. And indeed they do cause anguish, even years later. No one said they never happen. And as noted up thread, aircraft accidents are one of the leading causes of rescuer death and injury.

Condolences for the loss of your friends. I too have attended the funeral of a SAR friend. He was a helicopter pilot killed trying to take off with an injured recreational snow machine driver, at night in poor weather. The sad part was that from what we know, the injuries were probably not that severe, but the snow machine guy wasn't prepared to spend the night till the weather got better....

I had flown with that pilot on several occasions. He was a fine pilot, who was highly motivated and loved SAR work. The agency involved in that crash has now modified it's policies. These days they would probably not launch that mission under the same conditions. One problem with keeping rescuers safe is that they are sometimes TOO motivated, and take risks they shouldn't. We need to have procedures in place to clearly evaluate the risk vs reward of every mission. Even more critical is clear thinking by the command team, to reign in over eager SAR team members.

As in every other aspect of life, accidents will still happen, no matter how careful we are.