Subway accident a lesson

A citywide safety test of escalators and travolators ordered by the Beijing bureau of quality and technical supervision after Tuesday's accident at Beijing Zoo Station on Line 4 is a much needed safety overhaul of the expanding subway network.

An ascending escalator at the subway station suddenly started moving in the opposite direction on Tuesday morning, causing the death of a 13-year-old boy and leaving 30 people injured. The OTIS escalator was reportedly still in the guarantee period, and maintenance staff had conducted a routine check on June 22.

Initial investigations by Beijing's quality authorities showed the accident was caused by a malfunctioning component that suddenly loosened the drive chain and the failure of its protection mechanism to prevent the escalator from moving in the reverse direction. At a news briefing on Wednesday evening, a deputy director of the bureau said the "initial conclusion" is that there "are design and manufacturing faults" in the OTIS 513 MPE-type escalator installed at the zoo station.