Girl sent plea for help before attack

A 16-year-old girl seriously injured by a classmate who then leapt to his death on Wednesday sent an instant message asking for help from her boyfriend before the attack.

But she was unable to answer the phone when her boyfriend called back, police say.

The picture emerged yesterday of the desperate moments before Cheung Pui-ling suffered multiple wounds that left her in hospital. She was in a stable condition last night but was still not fit for a full police interview.

The attack was discovered at about 2pm on Wednesday after Lin Yiu-wai, also 16, leapt to his death from a 20th-floor flat at Man Wo House in Wo Che Estate, Sha Tin.

Officers believe Cheung retreated to the kitchen of Lin's home after he suddenly started saying strange things as the two teenagers revised together. She used her mobile phone to send the message for help through her Facebook account, a police source said. "But she was unable to answer the call when her boyfriend telephoned her," the source said.

Officers found the injured girl semi-conscious in the living room of the flat.

She was able to give police a brief account of the attack before passing out, the source said.