The Electrical & Mechanical Services Department today released its investigation report on the escalator incident in Langham Place in March.
The investigation found the escalator’s main drive chain was broken at the time of the incident, and the breakage was caused by metal fatigue.
It also found the broken drive chain device, which monitored the drive chain's operation, contained sticky grease formed from lubricant and dust.
One of the two compression springs in the device was also found to be locked before the incident.
The accumulation of grease and the locked spring led to the failure of the device to activate the auxiliary brake to stop the escalator. The escalator then reversed downward due to the weight of its passengers.
The department has suspended the registration of the escalator's engineer and repair worker for six months.
Director of Electrical & Mechanical Services Frank Chan said they failed to perform their duties.
"In terms of criminal offence, it will be subjected to another more thorough and more robust investigation in terms of what kind of expectation or performance they are supposed to do, what kind of thing they omitted to do and what they have done wrong.
"So these would be in the ambit of their criminal investigation and possible prosecution."
Since the incident, the department has made registered escalator contractors conduct special inspections on all 64 escalators in Hong Kong with a vertical rise of 15 metres or above, and no anomaly has been found.
Click here for the report.
