Friends and classmates yesterday mourned 16-year-old Hung Hoi-wai, who fell to her death on Monday. Hoi-wai wanted to go out to celebrate her birthday but was stopped by her parents. Around 6am on Monday, she climbed out of the window of her third-floor flat in Kowloon City Road and fell to her death. She had tied a nylon string around her waist and to the window frame to support herself, but it had snapped, police said. Hoi-wai suffered serious head injuries and was found lying motionless on the ground. A passer-by shouted for help and alerted Hoi-wai's 19-year-old sister, who called police. Hoi-wai, a Form Four student at New Asia Middle School in To Kwa Wan, was taken unconscious to Queen Elizabeth Hospital, where she was declared dead. The school's principal Wong Wai-ting described Hoi-wai as a good student. 'She was a positive and enthusiastic girl. She had a good relationship with teachers and was well-liked by students,' she said. Wong said Hoi-wai was good at academic subjects. Teachers had praised her for her work in organising school activities. 'We are shocked and saddened by her death,' the principal added. Hoi-wai's schoolmates created a Facebook page to offer condolences. They made their profile pictures black in a sign of mourning. 'Happy Birthday, Hung!' a friend, Rose Ann Wong, wrote on the site. 'I'm sorry that I haven't given you a present ... I just want you to know we will never forget you.' Another friend wrote: 'You were once a member of my prefect team. 'We have made it through tough moments in the training camp together, and it is sad that I can no longer work with you from now on.'