As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MKE - ON TAKEOFF ROLL, FIRE DETECTOR ACTIVATED ONE ENGINE NR 2 B-LOOP. (BOTH FIRE BOTTLES USED.) FOUND B-LOOP CONNECTOR APPROXIMTELY TWO FEET AFT OF OIL FILLER CAP CONTAMINATED WITH WATER. CLEANED CONNECTORS, BOTH LOOPS CHECKED OK. REMOVED AND REPLACED BOTH FIRE BOTTLES.