A schoolboy suffered "multiple blunt force injuries" when he fell 100ft to his death at a quarry, an inquest heard.
Myron Davies, 15, died and a 14-year-old girl was left fighting for her life after the tragedy near Pontypool, South Wales on July 6.
The pair fell at the former limestone quarry, and Myron's heartbroken family is desperate to learn how he died.
Police officers were called at 6.36pm and Myron was pronounced dead at the scene, the inquest opening heard.
A post mortem examination revealed a provisional cause of death as "multiple blunt force injuries to the head and trunk."
Coroner Caroline Saunders adjourned the hearing at Gwent Coroner's Court until April next year so more investigations can be carried out.
Gwent Police said the 14-year-old girl, who has not been named, remains in a critical condition in hospital.
Myron's mum, Sarah Davies, said: "As you can imagine as his family we are completely heartbroken and all his friends are devastated as we try to make it through each day after hearing this heartbreaking news.
"It's a mystery to what happened on this tragic day so if anyone has any information on what happened could you please come forward.
"As a mother I really need to know what happened to my son. We would also like to thank everyone for your kind messages and support at this devastating time."
She said Myron had lots of friends locally and loved being outside.
She added: "He was seen by the community on his motorbike and pushbike on a regular basis.
"Our son Myron attended Abersychan school, he was a popular boy and was loved by teachers and pupils. He was a happy boy, he always had a smile on his face."
Councillor Janet Jones, who represents Blaenavon, previously said: "This is a tragic incident, and the effects of it will have reverberations throughout the communities of Blaenavon and Abersychan.
"My thoughts are with the two families, and I'm sure the local community and the local community council will rally around to support them through this terrible time."
The 19th century quarry, once a hub for producing lime for local steel industries, was abandoned more than 50 years ago.
