Three years before the F3 culvert caved in at Piles Creek, near Somersby on the NSW central coast last June, Gosford City Council sought tenders for the repair of the rusted pipes.

Ms Bragg, 29, her nine-year-old nephew Travis, her partner Adam Holt, 30, and their children Madison, two, and Jasmine, three, all died when the road collapsed.

An inquest into their deaths heard that the Roads and Traffic Authority (RTA) knew of the propensity for such steel structures to fail “long before” the construction of the road began.

An Australian standard was issued in 1977 - five years before the Somersby diversion was built - reflecting the need for such structures to be concrete-lined, the inquest heard.

“As to this particular road and section of it, by 1984 the Roads and Traffic Authority (RTA) was aware that the culvert, and it would seem this particular one, was subject to corrosion,” counsel assisting the inquest Paul Menzies QC said.

The RTA recognised the need for concrete lining and gave constructing engineers directions in accordance, but it was not done, Mr Menzies said.

Responsibility for the road had been transferred in 1995 to Gosford City Council, which had called on the RTA to conduct an assessment of any repairs that needed to be done.

“Council observed that there was a fear that the council was accepting a liability rather than an asset,” Mr Menzies said.

After taking on the road, it became apparent to the council “some considerable time later that there was a serious problem with this road in the year 2000”, Mr Menzies said.

In April 2002 the section was overlaid with asphalted concrete to compensate for the subsiding of the road surface.

In a memo dated July 2004 the council sought advice on fixing the underlying structure.

“The problem is the bottom panel has been rusted out, water has been getting under the apron and washing out from around the pipes causing the road to sink,” read the memo yesterday tended in court.

“Is there (something) you could recommend to place or pump into the cavity to create a seal and/or replace the rusted the pieces?”

In-car camera footage taken by a highway patrol officer on the day of the collapse showed a significant dip in the road.

The family and friends of the deceased gasped as the footage was played in court.

“How this state of affairs was allowed to develop ... are all

questions which go to the manner and cause of death of these five

unfortunate people,” Mr Menzies said.

Senior Constable Mark Davies told the court the road had been sinking “for a long time”.

On the day of the collapse the

in-car camera of his highway patrol vehicle recorded a noticeable dip as it drove over the culvert.

The footage was played in court yesterday.

Mechanical examination of the Holt’s car revealed no faults, though Mr Menzies said the

presence of alcohol and cannabis in Mr Holt’s blood may have been a contributing factor.

The hearing continues in Central Local Court in Sydney.