CLEAN : Three dead 20 hurt as car rams Melbourne shoppers (2)

The transcript describes a chaotic scene where a maroon car, completely destroyed, caused panic by hitting several people. A loud bang, possibly a gunshot, was heard. The car stopped after hitting people, and the driver remained inside until police arrived and arrested him. The area was quickly evacuated and cordoned off by police, transforming from a crowded place to a scene of chaos.

What actions did the police take after the incident?

How did the atmosphere change from the beginning to the end of the incident?