Martin Mellish, 61, unexpectedly became a celebrity recently.

Walking in the street, dining in a restaurant or visiting a scenic spot, he would find himself being recognized by strangers who would greet him with a friendly "hello".

"They would say 'You are the laowai (foreigner) who helped an ambulance,'" said Martin, a US citizen teaching mathematics at a high school attached to Sichuan University in Chengdu, capital of Sichuan province. Cycling on his way to Chengdu No 12 High School, where he was scheduled to give a free English lecture on June 12, Martin happened to see an ambulance with its siren on trapped in a crowd of cars under an overpass near downtown Chengdu's Jiangxi Street.