An innocuous question posed by a kid a few years ago almost made Prime Minister Lee Hsien Loong cry at a conference yesterday (Oct. 4).

Speaking at OnePeople.sg Community Leader Conference where he emphasised on the importance of racial and religious harmony, PM Lee recounted an episode during a Racial Harmony Day celebration in a school in his Teck Ghee ward.

"I attended one of these exhibitions a few years ago in a school in Teck Ghee and the kids took me around. The kids were trained, they became docents – you know guides. So they took me through the whole exhibition, very good. Then at the end, we finished, I chatted with them. And then one of these young docents asked me, he said: 'Sir, when you were in school, did you also celebrate Racial Harmony Day?'

I was so taken aback. I said: 'No, I didn't celebrate Racial Harmony Day. On July 21, when I was in school, one year there was a riot. That's why you are celebrating Racial Harmony Day now.'

I think he understood me but in a way, he was not there, you don't want that generation ever to be there and yet you want the generation to understand what it is, which is precious, which is important, which we've got to safeguard together in Singapore."

PM Lee was referring to the racial riot on July 21, 1964 during a Muslim procession held to celebrate the Prophet Muhammad's birthday. Four people were killed and 178 injured that day.

He was a studying at Catholic High that year.

Watch the video here (from the 5:35 mark)