What was found
AT PUSHBACK, THE BATTERY CONDITION LIGHT CAME ON AND THE FLIGHT ATTENDANTS REPORTED FLAMES AT THE BASE BOARD BEHIND 2L LAV. PAX, F/A, AND SECOND OFFICER CONFIRMED FLAMES AND AN EXTINGUISHER WAS DISCHARGED. AIRCRAFT WAS EVACUATED PER THE CHECK LIST. FOUND WIRE BUNDLE BELOW LAV BURNT. SIGNS OF BLUE WATER STATION BU NDLE. SUSPECT INSULATION BREAK DOWN DUE TO BLUE WATER. NO CHAFING NOTED.