HONG KONG — An escalator malfunction in a Mong Kok mall on Saturday left at least 18 people injured. <br /> <br />The escalator at Langham Place on Argyle Street connects the fourth and eighth floors, and is one of the longest in Hong Kong, according to the South China Morning Post. <br /> <br />Video footage recorded by several witnesses and CCTV shows the packed, 45-meter-long escalator moving “up” suddenly change directions and start to move “down.” <br /> <br />Witnesses said it sped up to twice or three times its normal speed, causing shoppers to lose their balance, fall over and pile up at the bottom of the escalator. <br /> <br /> <br />Police said one man suffered a head injury and was taken to the hospital where he remained in serious condition as of Saturday night, the South China Morning Post reported. <br /> <br /> <br />Officials said the malfunction may have been caused by one of the escalator’s two breaks and its non-reversing mechanism.