Consider the following statements regarding safety during demolition of a multistory building:
1. Demolition need not proceed storey by storey
2. Floor openings, not used for material chutes, should be enclosed with adequate guard rails.
3. Before demolition starts all lath and loose plaster shall be stripped off throughout the building
4. Adequate and well-stiffened lateral bracing shall be provided for walls
Which of the above statements are correct?