Detectives start investigating

Detectives from Kowloon West regional crime unit are investigating Friday's collapse.

They will interview victims and witnesses about the incident and are seeking the property's owner, in order to uncover the reasons behind its collapse. They also want to talk to construction workers who were renovating a ground-floor shop in the building and who raised the alarm minutes before it collapsed. Officers will want to find out if anything they did was a factor in the collapse.

The Buildings Department will take rubble from the collapsed block for testing and conduct its own interviews with witnesses.

The coroner's court may also decide to hold inquests into the deaths of the four people killed.