Sadly, this has ended in tragedy. One of the canyoners, 15 y.o Nicholas died in a rockfall only hours before rescuers located the group.
If anyone wishes to go bushwalking, canyoning, caving etc in the Blue Mountains, you can get a free GPS personal locator beacon from our local Parks and Wildlife Offices and police stations. If you are in distress or lost, it sends a signal out to the rescue services so they can locate you. Sadly, this group did not have one.