Youngsters have been urged to be wary about entering caves and disused quarries following the death of a 16-year-old who fell victim to a rockfall in Shropshire.
West Mercia Constabulary said the Health and Safety Executive is continuing to assist its inquiry into the death of Aiden Brookes near Bridgnorth.
Although officers have described the rockfall as a tragic accident, Chief Inspector Martin Whitelegg said the incident demonstrated the potential dangers posed by caves, former mine-workings and quarries.
"We are still investigating the full circumstances and the reason why the upper parts of the cave collapsed, but this tragedy clearly demonstrates the inherent dangers posed by caves, old quarries, mines and the like," Mr Whitelegg said.
"Great care is obviously required when entering such places and people should stay well clear unless they are properly equipped and know exactly what they are doing."
The officer added that the group of friends camping out in the cave had lit a fire underneath a sandstone overhang which may have contributed to the rockfall.
"We will do our utmost to establish the cause of the collapse in preparation for the coroner's inquest," Mr Whitelegg said. "I would urge parents, schools and those who run scout and guide groups to make young people aware of the hazards."
Aiden, who lived about a mile away from the cave, was struck by rocks and rubble and was certified dead shortly after being taken to the Princess Royal Hospital in Telford.
An 18-year-old girl was also hurt and admitted to the hospital with serious injuries.