Rozelle building completely knocked down

The building next to an inner Sydney explosion site that killed three people, including a baby boy, has been fully demolished.

Police finished knocking down the corner block on Darling Street premises in Rozelle on Friday after working through the night to complete the demolition job.

Officials will turn their attention to examining the crime scene next door.

Bianka O'Brien, her one-year-old son Jude and neighbour Chris Noble were all killed in the explosion at a convenience store during the early hours of September 4.

After reports of an accelerant being found at the explosion site, investigators have collected hours of CCTV footage from petrol stations on nearby Victoria Road.

The stations handed over up to four days' worth of footage leading up to the fatal explosion.

Local businesses have been affected by the tragedy, with a section of the main shopping strip, Darling Street, remaining closed to traffic for the past week.

Leichhardt mayor Darcy Byrne said the local economy had suffered a $1.5 million hit in the past week.

To combat the losses, the local council has implemented a range of measures to lure Sydneysiders back to the area, including a marketing campaign titled "Rozelle Needs You - Can you shop local?"

An open-air concert will be held in Rozelle on Sunday, September 21, to bring the local community together, and a street fair will be staged on Darling Street once the road has reopened.

Rebates have been offered to affected property and business owners.

"The important step forward is getting the street reopened and we need to work urgently to make sure Rozelle gets back on its feet," Mr Byrne said.

Meanwhile an appeal has been set up for John O'Brien, the husband who lost both his wife and son, their family home and all their belongings in the devastating fire.