A father-of-eight died after going for a swim in a pond on an alcohol fuelled camping trip.
But after swimming in the water for 20 minutes he called out for help and went below the surface.
The emergency services were called but Mr Lerwill’s body wasn’t retrieved until the next day after a multi-agency search proved difficult.
An inquest hearing at Newport Coroners’ Court on Tuesday heard a statement from Mr Lerwill’s friend Paul Davies who accompanied him on the camping trip.
He said they drove to Pen y Fan Pond in Mr Lerwill’s van and were met by Mr Davies son.
The witness said: “We had a few beers and I would say David was drunk. We started mucking around saying we were going to swim across the pond.
“I can’t swim but David jumped into the pond, he was standing in parts of the pond and then he started swimming.
“I would say he was in there for 20 minutes when I heard him shout ‘someone help me’. Three other women were around the pond and one of them shouted ‘he gone under’.”
Mr Davies stripped to his underwear and entered the water in an attempt to save his friend.
He added: “The water was freezing. I tried to go in as far as I could but I couldn’t see him.”
Bystander Molly Williams was at Pen y Fan Pond and was walking with a friend. She said upon entering the pond, she saw group of males and remarked to her friend ‘look at those boys, they’re p*****’.
She said one of the group went into the water and walked up to his waist. They carried on with their walk and when they returned to the entrance they could see the emergency services were in attendance.
Another witness Emma Padfield was running at the pond that night.
She said she saw Mr Lerwill entering the water in his pants and could see his friends on the pier drinking, encouraging him to get into the water while shouting and laughing.
Ms Padfield said she saw him begin to struggle and he shouted “boys” and seemed panic stricken. She phoned the police and threw a ring into the pond while trying to keep her eyes on Mr Lerwill until he went under the water.
PC Benjamin Hardy was the first of the emergency services to attend the scene and made his way to the edge of the pond to see if he could see Mr Lerwill.
He was approached by a man who appeared to be drunk who said Mr Lerwill had gone under the water.
A search was conducted involving the fire brigade, a police diving team and mountain rescue but the search was suspended at 12.36am. It resumed at 7am on March 26 and Mr Lerwill’s body was recovered at 2.54.
He was pronounced dead at the scene and was identified by his father in hospital.
A post-mortem examination was carried out which found Mr Lerwill’s medical cause of death as drowning.
A toxicology report found the presence of alcohol and medical drugs in Mr Lerwill’s body but it was not possible to determine the role they played in his death.
In reaching her conclusion, coroner for Gwent Caroline Saunders said it was not known whether Mr Lerwill had been overcome by the cold or had become entangled but his decision to enter the water was “fatal”.
She added: “David went for an impromptu alcohol-fuelled swim in Pen y Fan Pond and got into trouble and despite the actions of his friends and the emergency services he could not be found until his body was retrieved the next day.”
Ms Saunders recorded a conclusion of misadventure.
Speaking at the time of his death, Mr Lerwill’s family paid tribute to their son, brother and father whose loss they described as “absolutely devastating” and “truly heartbreaking”.
Lisa Lerwill, David’s sister, said: “It still doesn’t seem real – how can he be gone? How are we never going to be able to see him again? Our lives will never be the same without him.
“David tragically had to leave behind his eight beautiful children who treasured and worshipped him and loved him so dearly.
“They no longer have their dad to support them, who would always do absolutely everything he could for them – he loved them all so much, he lived for his children. He was an amazing dad who was always there for all of them.
“David was definitely one of a kind, he had a heart of gold [and] would do anything for anyone, especially his family – he was definitely a family man.”