As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DFW - FLT 558 - WHILE PARKED AT THE GATE ELECTRICAL POWER WAS INADVERTENTLY SWITCHED TO GROUND SERVICE BUSS WHICH INTURN OVER TEMPED THE PACKS CAUSING SMOKE IN THE CABIN. THE PASSENGERS WERE EVACUTATED. THE SMOKE WAS CLEARED FROM THE CABIN. ENGINE RUNS AND PACKS WERE TESTED, OPERATION NORMAL. (M)