An escalator in a crowded Hong Kong shopping center malfunctioned on Saturday, injuring at least 18 people. Shoppers at Langham Palace lost their balance and fell as the 45m escalator suddenly reversed direction. One woman who injured her leg in the accident said the escalator was moving twice as fast as the normal speed. Officials said the malfunction was probably caused by a damaged driving chair of the escalator. A braking device also malfunctioned.A witness said that because people lost their balance and fell off, more than 10 people were seen piled up near the base of the escalator. Mall officials said they are investigating why those auxiliary brakes did not kick in. They said that the escalator passed a biannual safety inspection on March 23.The escalator that malfunctioned is one of the largest indoor escalators in shopping haven Hong Kong. The escalator is currently cordoned off while the maintenance team and other officials are conducting further investigations. Some shoppers caught the escalator accident on video where the affected shoppers were screaming, and shared those online as well as with some media outfits.