MOON, Pa. -- Hundreds of children from the Pittsburgh area previously scheduled to leave Sunday morning, had to wait until 8 p.m. for a new flight to Sydney, Australia when their charter plane developed a mechanical issue.

The problem was identified and corrected, but the delay caused the plane's crew to time out, and a new one had to be assembled.

The group is headed to an event called World Youth Day, which is organized by the Roman Catholic Church. The international convention is held annually.