SINGAPORE: The collapse of a ventilation duct at Shaw Theatres in NEX shopping mall was caused by overloaded brackets due to the weight of accumulated water, authorities said on Monday (Dec 7).
Two people were injured when the duct collapsed during a movie screening on Aug 30. Footage of the incident showed the duct had fallen across several rows of seats.
The cinema was temporarily closed as a safety precaution.
The Building and Construction Authority (BCA) said a “significant amount of water” had accumulated in the layers of acoustic material surrounding the air-conditioning and mechanical ventilation duct. This was caused by “unforeseen excessive condensation”, it said.
The weight of the water eventually overloaded the brackets supporting the air-conditioning and mechanical ventilation duct, causing them to give way.
After the incident, BCA said it instructed NEX to appoint a professional engineer to carry out an investigation and to recommend rectification measures.
BCA said it has reviewed the professional engineer’s investigation report and also completed its own investigations with similar findings.
Owners of other cinemas in Singapore have also been instructed to conduct checks on their air-conditioning and mechanical ventilation systems and ducts, BCA said.
“Based on the checks in other cinemas, including BCA’s independent checks, no such excessive condensation and similar dropper ducts were observed,” it said.
BCA added that it will issue an advisory to the industry and building owners on the importance of regular maintenance and to share good practices for the design and installation of such systems.