A 2½-year-old girl, who returned Hong Kong with her mainland mother for a family reunion three days ago, died after falling out of window from her ninth-floor apartment in North Point on Monday.

Hong Kong-born Yim Ka-ying was playing beside her mainland aunt, 36, on a sofa in the flat’s living room in Tsat Tse Mui Road when the tragedy happened at about 11.30am.

The 45cm-tall window is right behind the sofa.

“The toddler played and climbed around beside her aunt on the sofa, suddenly climbed up, fell out of the window and disappeared,” one police officer said.

Police said her aunt discovered her disappearance in a second. “She went mad and immediately ran downstairs to seek help from a security guard,” he said.

Yim, the only child in the family, fell on to the first-floor podium of the building outside a kindergarten.

She was declared dead in Pamela Youde Nethersole Eastern Hospital in Chai Wan shortly before 1pm.