MEXICO CITY — The wiggling fingers of a young girl trapped in the rubble of her collapsed school in Mexico City raised hopes among hundreds of rescuers working furiously Wednesday to try to free her — a drama that played out at dozens of buildings toppled by the powerful earthquake that killed at least 223 people.But it was the ongoing rescue at the Enrique Rebsamen school, where 25 people including 21 children perished, that was seen as emblematic of Mexicans' rush to save survivors before time runs out.Helmeted workers spotted the girl buried in the debris early Wednesday and shouted to her to move her hand if she could hear. She did, and a rescue dog was sent inside to confirm she was alive.Hours later the crews were still laboring to free her, as images of the rescue effort were broadcast on TV screens nationwide. Workers in neon vests and helmets used ropes, pry-bars and other tools, frequently calling on the anxious parents and others gathered around to be silent while they listened for any other voices from beneath the school.At one point, the workers lowered a sensitive microphone inside the rubble to scan for any noise or movement.