COLOMBO, Sri Lanka (AP) -- Doctors and aides abandoned the only hospital in Sri Lanka's war zone amid unrelenting shell attacks, a health official said Thursday, as thousands of civilians braved rebel gunfire and fled across the front lines, according to the military. The medical staff was huddling in a nearby bunker because of the nonstop shelling, and could hear the cries of hundreds of patients unable to leave the hospital begging for food and water, according to a health official in the war zone.