Days of anguish over a river tragedy in Australia Published duration 6 March 2017

image copyright 9news.com.au image caption Police examine the Murray River on the Victoria-New South Wales border

A tragedy involving two young boys who were allegedly attacked by their mother has dominated Australian headlines since Thursday.

According to police, the woman tried to drown the boys, aged five and nine, in the Murray River, which divides the states of Victoria and New South Wales (NSW).

The younger boy was found dead two days later. His brother managed to escape but was mauled by a dog and injured, police said. He is now recovering in hospital.

As the mother faces charges of murder and attempted murder, grief has swept the community amid claims the tragedy could have been prevented.

What do police allege happened?

The 27-year-old woman, who cannot be named for legal reasons, allegedly brought the boys to the Murray River at Moama, a border town 640km (398 miles) south-west of Sydney, late on Thursday afternoon.

A court heard she tried to hold the nine-year-old boy under water, but he was able to wriggle free after his younger brother started screaming.

The older boy was then attacked by a pit bull dog, which had reacted to the alleged attack, police said. The boy was flown to Melbourne's Royal Children's Hospital suffering serious bite wounds.

The woman presented herself to police a few hours later.

The body of the five-year-old boy was not found until Saturday morning.

Could the tragedy have been prevented?

The boys had been living with their grandmother for about 18 months. She learned of the younger boy's death while with his brother in hospital on Saturday.

"I'm simply heartbroken," the grandmother told the Sunday Herald Sun.

She has also claimed, through her lawyer, that authorities had missed several "warning signs" which might have prevented the tragedy.

Lawyer Dale Brooks said the family had raised concerns with police, the Department of Family and Community Services in NSW and the Department of Corrective Services.

Mr Brooks said the children had only been reunited with their mother in recent weeks.

image copyright 9news.com.au image caption Police allege the woman tried to drown her two boys

"There was ample time to save these children," he told the Sydney Morning Herald.

What are the authorities doing now?

Since the younger boy's body was found, the public has placed items including flowers and teddy bears at the scene. Tributes have also been left at his home in Deniliquin, about 75km away.

As the family's criticism was renewed, NSW Premier Gladys ­Berejiklian intervened on Sunday to confirm all government agencies' handling of the case would be reviewed.

"We'll be instigating investigations but also co-operating with all the authorities to make sure we get to the bottom of this," Ms Berejiklian told reporters.

"This is a human tragedy of the highest proportion."

A court on Monday heard the accused woman would undergo a psychiatric evaluation before the next court hearing on 2 May.

"I really got the distinct impression she doesn't know what's going on," her lawyer, Peter Hebbard, said outside court on Saturday. "Not in terms of the legal side of it, but in terms of just what's happening."

Did the dog save the boy?

The owner of the dog involved in the incident claimed the animal was trying to save the nine-year-old boy, not hurt him.

The pit bull, named Buddy, was seized by Murray River Council after the incident, at the request of police.

But a petition to save the dog had gained almost 50,000 signatures on Monday. The organiser described Buddy as a gentle dog who deserved to be "labelled a hero".