It was a night that promised to bring joy and light to Sydney's iconic Bondi Beach as crowds of Jewish families gathered at a park to celebrate the first night of Hanukkah, also known as the festival of light.

They were among thousands of other swimmers, surfers, and sunbathers who had flocked to Australia's most famous beach on a scorching summer's afternoon.

But not long after the Hanukkah event kicked off at 17:00 local time and the first free donuts were doled out, festive music was drowned out by the sounds of screams and the echo of gunshots.

It's unclear exactly when the first shot was fired, but the initial call to police was made at 18:47. In the minutes that followed, two gunmen would kill at least 15 people and injure dozens more, authorities said.

A local high school teacher, Chavi, told the BBC she dropped to the ground to protect her baby as bullets were flying above us.

It was pandemonium and chaos, another attendee, who identified himself as Barry, said as he described watching a throng of people trying to escape the scene that had suddenly devolved into a nightmare.

In one video verified by the BBC, upbeat music from the Hanukkah event can still be heard in the background as people crouch down and shots are heard, interspersed between shrieks.

The eerily jubilant music continues playing while the camera pans over the grass, revealing prostrate bodies completely still, their condition unclear.

Panic soon spread from the park to the sand, where videos show terrified beachgoers sprinting away from the gunfire.

Screams, honking car horns, and ambulance sirens fill the air in the next chaotic minutes. Some cars crashed as people desperately tried to get away, witnesses have told the BBC.

A nearly 11-minute video, verified by the BBC, provides perhaps the clearest timeline of the attack - though it is unclear exactly how far into it the recording started.

It begins as the two gunmen make their way across Campbell Parade - the long stretch of road, lined with cafes, that curves around the beach - and onto a pedestrian bridge above the park where the Hanukkah event was taking place.

It is from there that two men - named as Sajid Akram and his son Naveed - allegedly use the elevated position to carry out the remainder of the attack, using what an expert told the BBC were two sporting shotguns.

Police later confirmed that one of the gunmen, Sajid Akram, was found dead at the scene, while the other was critically wounded and taken to the hospital.

Authorities continue to investigate the background of the attackers as the vigil for the victims begins, highlighting the tragic impact of the night that started with a celebration.