Dashcam video reveals moments before double fatal crash

Shocking footage has emerged of the moment a car in early afternoon traffic on the Sydney Harbour Bridge went off course and triggered deadly chaos. Warning: Confronting

Shocking dashcam footage has captured the lead up to the horrific collision that killed two men on the Harbour Bridge on Thursday afternoon.

The vision emerged just hours after the deadly crash which shut down the bridge on Thursday, showing exactly what caused the crash.

At 1.35pm, the male driver of a blue hatchback can be seen travelling in the last northbound lane in the middle of the bridge, before it veers into the first southbound lane, colliding head-on with a white Hyundai.

The force of the impact sends the Hyundai spinning across three lanes and into the path of a bus. The blue hatchback then collides head-on with a white sedan.

Debris, smashed glass and a tyre can be seen flying through the air, as cars around them slow to a stop.

The scene of the fatal multi-vehicle crash on the Sydney Harbour Bridge

The force of the impact between the blue hatchback and the Hyundai is so strong that both drivers died as a result. They are yet to be formally identified.

The driver of the bus was uninjured, while the driver of the white sedan and the driver of a fifth vehicle suffered minor injuries, and were taken to Royal North Shore Hospital.

Four lanes were travelling northbound at the time of the collision, while two were travelling south.

Drivers in cars surrounding the collision emerged from their vehicles to assist, with police praising them for the efforts afterwards.