A memorial service for hundreds of students of Juyuan Middle School in Dujiangyan, where a mother held a picture of her son, turned into an angry protest on Tuesday. Some parents said local officials had known for years that the school was unsafe but refused to take action Others recalled that two hours passed before the rescue workers showed up; even then, they stopped working at 10 p.m. on the night of the earthquake and did not resume their search until a.m. the next day.A memorial service for hundreds of students of Juyuan Middle School in Dujiangyan, where a mother held a picture of her son, turned into an angry protest on Tuesday. Some parents said local officials had known for years that the school was unsafe but refused to take action. Others recalled that two hours passed before the rescue workers showed up; even then, they stopped working at 10 p.m. on the night of the earthquake and did not resume their search until 9 a.m. the next day