Kristopher McDowell, fell 120 feet to his death from the Pontcysyllte Aqueduct as he was walking home with friends in the early hours of the morning.
An inquest in Ruthin heard how the 18-year-old had squeezed through the cast-iron railings alongside the towpath, but then plunged backwards when one of the uprights he was clutching came away.
Mathew Breeze, Alex McLeod and Jordan Evans had all walked along the towpath to meet Kristopher as he walked home after finishing his shift at McDonalds’ restaurant in Chirk on May 30, 2016.
They met up with him on the Froncysyllte side and shared two cannabis joints before going onto the 200-year-old aqueduct, which is a UNESCO World Heritage Site visited by 200,000 people a year.
In a statement read at the hearing, Jordan Evans said he had told the others he was scared of heights, especially in the dark, but Kristopher said: “I’m not scared to hang over the edge.”
He then stepped through the railings, standing on a narrow ledge, but fell backwards.
Mathew, who was 17 at the time, said his friend was easily able to get through the bars.
“As soon as he put weight on it it came away,” he said.
All three youths ran down to the spot below the aqueduct and tried to apply CPR, however a paramedic who was soon on the scene confirmed that Kristopher had died
Pathologist Dr Mark Atkinson gave the cause of death as chest trauma.
Kristopher’s mother, Mrs Samantha McDowell, of Coronation Street, Cefn Mawr, said in a statement read at the inquest that her son, former pupil of Ysgol Dinas Bran, Llangollen, should not have been able to get through the railings .
She acknowledged that he had been foolish in doing what he did, but added: “The fact is that if the bar had not come away Kristopher would still be here today.”
“I understand that lots go through and walk the full length of the canal on the outside.”
The jury was shown a five-minute video by the Canal and Rivers Trust, the charity responsible for the upkeep of the structure, outlining the inspection procedures and routines.
Martin Watson, the trust’s length inspector responsible for that section of the canal, told the inquest that he had carried out the regular monthly check on May 5, 2016, and that entailed striking each upright with a stick of baton, when any loose upright would make a different sound.
On that occasion, however, he did not identify any issues.
John Gittins, coroner for North Wales East and Central, asked him: “Do you think that when you did that inspection you may have missed something about this upright which came away?”
Mr Watson replied: “No”.
When Mr Gittins asked whether he felt the uprights were secure, he replied: “It was fit for purpose”.
The inquest heard that following the tragedy a thorough examination of the structure revealed 332 of the 1,440 uprights to be loose, but Mr Watson commented: “A slight movement does not necessarily mean they are unsafe.”
The previous annual inspection by an engineer, when the structure was more thoroughly examined, took place in July, 2015 .
The hearing continues.