The girl, Mei Qingwen, is admitted to the ICU at the No 1 Affiliated Hospital of Harbin Medical University with kidney and lung damages. [Photo by Liu Mengxin/for China Daily]

To thank the at-the-time anonymous man for saving her grand-daughter, Yu got in contact with the local news broadcasting station to find the "savior".

"My neighbors told me that he was a middle-age, middle-height man with a pair of glasses. But with the effort of many people, we managed to finally find him," she said.

"I can't express my thanks with simple words. I couldn't image what would of happened without Xiao's help. He is the savior of my whole family."

Yu added the incident occurred when Mei found was left alone while her grandfather attended the market. She said Mei was trying to signal him through the window when she slipped and fell.

Mei was born with hearing disability and could speak after undergoing cochlear implant surgery.

"Her cochlear implant was out of power by accident, so she couldn't hear Xiao," Yu said.

Xiao's story went viral online. Some netizens call him "Glasses Man".

Wang Zuosheng, the schoolmaster of No 11 Senior High School, said he was not surprised Xiao ran to help.