An 84-year-old grandfather has died in hospital on the Gold Coast after he and his family were allegedly trapped inside their home during a suspected arson attack. Bob Marsh succumbed to his injuries on Thursday, having suffered burns to 50 percent of his body.

The incident occurred at a property on Sickle Avenue at Hope Island around 11:45 p.m. on Tuesday. Mr. Marsh, his daughter Kathy Windsor, 59, and her family were reportedly unable to escape the flames because keys had been removed from deadlocks, effectively locking them inside.

Mr. Marsh's daughter, Ms. Windsor, remains in critical condition in hospital. She reportedly broke her back while jumping from a balcony to escape the fire. Her new partner also sustained burns and is in critical condition, while her adult son escaped the blaze without physical injury.

A 38-year-old man, believed to be responsible for the attack, died at the scene. Investigations are ongoing to confirm his identity. Police are treating the incident as linked to domestic violence and noted that officers had responded to the property the week prior. The alleged perpetrator was reportedly the subject of a domestic violence order.

Mr Marsh's daughter Kathy Windsor is fighting for life in hospital after she broke her back jumping from a balcony to escape the flames

Paramedics and firefighters were on the scene. Neighbours Eli Bijl-Kakoi and Meihana Pauling described hearing screams and a shout of "My ex is trying to kill us." They assisted in forcing open the garage door to help the family escape. Detective Superintendent Chris Ahearn stated that the violence was unacceptable and urged the public to report such incidents.

The damage to the house was extensive

The family released a statement calling the event "the most heartbreaking time of our lives" and expressed gratitude for the kindness of others. The fire caused extensive damage to the home, with parts of the building partially collapsing and the roof destroyed.

A police officer is seen collecting a piece of evidence at the home on Sickle Avenue on the Gold Coast on Wednesday morning

Pictured, emergency services arrive at the scene

Fire crews worked to put the blaze out on Tuesday night