Under Victoria's road rules, a heavy vehicle driver must not park their vehicle in a way that obstructs traffic. If they must stop on a road at night due to a breakdown, what is the FIRST action they should take?

1. Phone the employer before taking any other action
2. Turn on hazard lights and switch off the engine immediately
3. Apply the park brake, turn on hazard lights, then deploy warning triangles as required
4. Wait inside the vehicle for rescue without activating any lights