Public health officials struggled to keep about 1,500 teenagers in quarantine yesterday, a task that proved insurmountable when some left their confinement to have fun. On the first day of quarantine for students of Father Michael McGivney Catholic Academy, just north of Toronto, one was already out shopping, while another invited friends to a concert where he was going to be playing last night. Murray McQuigge, a spokesman for York Region's public health department, knows all too well that grounding an entire school without any supervision is far from easy. "I'm sure that after this the parents of those kids...