Please answer the following question: I know that the answer to the question "Where and when would you find a sad mom?" is in "On Children's Day, June 1, 2008, many parents went to the rubble of schools to mourn for their children. The surviving children, who were mostly living in relief centres, performed ceremonies marking the special day, but also acknowledging the earthquake.". Can you tell me what it is?
A:
On Children's Day, June 1, 2008, many parents went to the rubble of schools