A 20-year-old man is facing a string of charges after he allegedly crashed into a brother and sister on their way home in Sydney's south-west on Friday night, killing them both.

Alina Kauffman, 24, was picking up her 15-year-old brother Ernesto Salazar from work just after 9pm when a black Mercedes crashed into their car metres from their home in Heckenberg.

Police allege the black Mercedes and the pair's Toyota Echo collided head-on, before the Mercedes hit a Toyota Rav4 and flipped on its side.

READ MORE: John Farnham gives You're the Voice song to the Yes campaign

The two occupants of the Rav4 were not injured.

Paramedics treated Alina Kauffman and her brother Ernesto but they could not be saved.

The driver of the black Mercedes allegedly fled the scene but attended Liverpool Police Station at 2pm the following day, where he was arrested.

Police announced the charges early today, after an emotional outcry from the pair's mother Angelina Kauffman at the crash site yesterday.

"My babies, they took them from me, my babies," she said.

"My kids were going to help people, my kids wanted to make a difference in this world, my kids were good people."

READ MORE: 'Margaritaville' singer Jimmy Buffett dies aged 76

Distraught friends and strangers joined her in laying flowers at the scene of the crash.

Alina was a dedicated nursing student with a kind heart, while Ernesto was an animal lover who was working at Kmart while saving for his first car.

The 20-year-old has now been charged with driving dangerously and negligently causing death, as well as failing to stop at the scene of a crash and driving while disqualified.

He will appear before Parramatta Bail Court today.

Another 18-year-old handed himself in to police yesterday and was released without charge, but police are still searching for two passengers of the Mercedes.

Two couples in their 70s who lost their lives in a quadruple fatal in northern Victoria have been remembered as wonderful members of their community.

Two siblings and their partners had been travelling to Melbourne to visit loved ones when the tragedy occurred on Thursday, leaving a small NSW town in mourning.

Trevor and Lorraine Breen, pillars of a country community, were tragically lost in a split second on the Hume Freeway, along with Trevor's sister Kerry Capes and her husband Noel.

READ MORE: Mum distraught after kids killed metres from home in Sydney crash

The two couples spent their early lives in the NSW town of Lake Cargellico, six and a half hours north-east of Melbourne.

Noel had recently returned to area to work in farming, while Trevor and Lorraine had moved to Wagga Wagga.

READ MORE: Tiny tablet provides huge results for girl with rare disease

A lifelong friend of the two couples, Paul Phillips, paid tribute to them all on Saturday as plans for a memorial in their hometown begin.

"People we can't afford to lose – as simple as that, wonderful people," Phillips told 9News.

"To lose four people who had the community standing that they did, in this area, is nothing less than devastating."

Victoria Police have said a moment of inattention may have led to the loss of the four lives after their car collided with a B-double truck near Chiltern around 10.30am on Thursday.

"After the community heard about it, Friday was a dead day in Lake Cargellico," Phillips told 9News.

"We'll certainly have something to remember them by, no question or doubt about that at all."

American singer-songwriter Jimmy Buffett, best known for his 1977 hit Margaritaville, has died aged 76.

"Jimmy passed away peacefully on the night of September 1st surrounded by his family, friends, music and dogs," a statement from his family on his website announced.

"He lived his life like a song till the very last breath and will be missed beyond measure by so many."

READ MORE: Elton John hospitalised after 'slip' at home

The family mentioned no cause of death in its statement.

Margaritaville was an easy-listening classic, in which the main character of the song drowns his sorrows in margaritas on account of a failed romance.

It contains the memorable line: "Some people claim that there's a woman to blame but I know it's my own damn fault".

READ MORE: Taylor Swift smashes record with 100 million Spotify listeners

Later in Buffett's life, Margaritaville became the name of a range of businesses and products in his business empire.

Buffett was still touring and performing shortly before his death but had no upcoming tour dates despite rumours of more shows across 2023 and 2024.

More to come.

A man has been arrested by police after a crash in Sydney's south-west overnight, which left two people dead.

Emergency services were called to Sadleir Avenue in Heckenberg, about 9.20pm on Friday after reports of a multi-car crash.

Police said a black Mercedes and a Toyota Echo collided head-on, before the Mercedes hit a Toyota Rav4 and flipped on its side.

READ MORE: Burger chain stores set alight in Brisbane

NSW Ambulance paramedics treated the driver of the Echo, a 24-year-old woman, and her 15-year-old male passenger however, they both died at the scene.

9News understands the older sister was picking her younger brother up after he finished a shift working at his new job at Kmart.

The two occupants of the Rav4 were not injured, while the occupants of the Mercedes allegedly left the scene.

Police arrested a 20-year-old man at 2pm today at Liverpool Police Station.

No charges have been laid and inquiries are continuing.

Police have arrested and charged a 34-year-old man with murder.

‘I don’t know how I could ever go through this alone’, mother says as community rallies.

His commitment does rely on the outcome of a new inquiry into Covid-19.

OPINION: Labour hopes dental care policy lands better with voters than GST off fruit, veg.

The new memorial track should be open by Christmas or shortly after.

Kāinga Ora stand by the design of the homes, which have yet to be completed.