A search is under way for a swimmer who disappeared at Maroubra Beach in Sydney.

Volunteers and vessels from Marine Rescue Botany Port Hacking and Marine Rescue Middle Harbour are searching for the man with water police.

The man, who police believe is in his 30s, failed to resurface after going into the water just before 4pm today.

READ MORE: Two girls fighting for life after house fire in Townsville

READ MORE: Millions get sweet relief after week of scorching, record-breaking heat

"Conditions are not favourable offshore this afternoon, with choppy seas and squally rain showers," Marine Rescue NSW Inspector Andrew Harding said.

"Volunteer crews on board Middle Harbour 30 and Botany Hacking 32 will continue searching this evening until instructed otherwise by NSW Police Marine Area Command."

READ MORE: British man in his 70s arrested over alleged cruise ship assault

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A spokeswoman for Fire and Emergency said the department “does not condone the behaviour”.

A man has died after crashing his bike at a skate park in Adelaide on what witnesses say was his first day of riding.

The man from Pooraka in the city died in hospital after the freak accident.

Sam Inwood, 27, died after the accident last week.

Friends described him as a kind, caring person and witnesses warned of the dangers of failing to seek urgent medical help.

READ MORE: Millions get sweet relief after week of scorching, record-breaking heat

Robert Lonie was at Golden Grove skate park when Inwood crashed and fell off his BMX bike about 2pm on Thursday.

"I don't think he was aware of how bad he got hit," he said.

"We put him in the shade and sort of asked if he's alright."

READ MORE: British man in his 70s arrested over alleged cruise ship assault

The victim took himself to hospital the following day before passing away in care.

"His friend had told me he had only just started riding that day, so I think it's a culmination of inexperience, a big impact and then not doing anything about that injury," Lonie said.

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Heartbroken friends remembered Inwood as a kind, gentle and caring person willing to help anyone.

Witnesses say the tragedy is a stark warning to take every possible precaution when it comes to safety and health.

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Two children are fighting for life after a house fire in Townsville.

Emergency services rushed to the home in Gum Court, Bushland Beach about 5.30am today.

Authorities were forced to smash the top floor window to enter the flaming building and pull out the girls, aged two and 13.

READ MORE: British man in his 70s arrested over alleged cruise ship assault

Police said they were taken to Townsville University Hospital in a life-threatening condition.

Two other children are also in hospital in a stable condition.

Two police officers were treated for smoke inhalation and taken to hospital as a precaution.

Investigations are ongoing.

READ MORE: Parents of Sydney Harbour shark attack victim, 12, join poignant Bondi paddle out

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$20k was spent on Louis Vuitton after a victim handed over bank card for ‘forensic clean’.

The Black Cat vessel capsized near Akaroa carrying 38 passengers and three crew members.

The loss will likely see Hooker drop further down the UFC’s lightweight rankings.

Emergency services were called to the scene at 12.15pm.

Repairs are underway today, with detours and delays expected for motorists.

Brian Boyd says he did not know about Jeffrey Epstein’s crimes when they first met.