MEXICO CITY (AP) — Rescuers and volunteers are frantically digging through the rubble of collapsed schools, homes and apartment buildings looking for survivors of Mexico's deadliest earthquake since 1985 as the number of confirmed fatalities climbed to 248.

Adding poignancy and a touch of the surreal, Tuesday's magnitude 7.1 quake struck on the 32nd anniversary of an earlier temblor that killed thousands, and came just two hours after earthquake drills were held across Mexico to mark the date.

One of the most desperate rescue efforts was at a primary and secondary school in southern Mexico City, where a wing of the three-story building collapsed into a massive pancake of concrete floor slabs. The federal Education Department reported late Tuesday night that 25 bodies had been recovered from the school's wreckage, all but four of them children.