A worker was standing adjacent to an L-shaped brickwall, which was to be demolished. The two lengths of the wall were connected by a reinforced concrete tie beam. While a mini excavator breaker was clearing debris from the base of the wall, the wall in front of the excavator collapsed outwards. The connecting tie beam then pulled down the other adjoining wall, causing it to topple inwards. The falling wall struck the worker standing next to it and pinned him under. The worker was brought to the hospital but he subsequently succumbed to his injuries. Initial investigations revealed that the wall might not be adequately anchored into its foundation.
- Conduct risk assessment: Prior to the commencement of work, a risk assessment should be carried out to determine the potential hazards and risks that might arise during the demolition work. Control measures and safe work procedures must be established to mitigate the risks, and be communicated and implemented to ensure the safety and health of the workers involved. The key hazard in this case was the wall that destabilised during the demolition works.
- Cordon off wall/structures to be demolished: Personnel not directly involved in the works should not be allowed in close proximity with any walls or structures that are scheduled to be demolished; Working areas should be cordoned off.
- Use props or wire ties: Whenever the stability of the walls/structures being demolished are in doubt, props and wire ties should be used to support the structure prior to and during the demolition.
- Deploy trained personnel: Personnel operating machinery or equipment should be properly trained and should posses appropriate certifications. Checks should be carried out by the management team to ensure that all workers and operators are properly trained and certified to carry out the works assigned to them.
- Singapore Standard SS CP11: Code of Practice for Demolition
- Workplace Safety and Health (Construction) Regulations 2007
- Ministry of Manpower’s Risk Assessment Guidelines.
- WSH Council’s Technical Advisory for Demolition
Source: WSH Alert Bulletin, 6 Oct 2010, Ref: 1011064