As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FWD PIT L/H TRANSITION PANEL STA 500K+6 TO 500L HAS CORROSION. GROUNDED - YES. REMOVED CORROSION FROM THE FWD PIT L/H TRANSITION PANEL AT STA 500K+6 TO 500L IAW B737-900ER SRM 53-00-53-1A-2.2.D ORIG THICKNESS IS .040 IAW B737-900ER SRM 53-30-53-01-2 TABLE 2. REMOVED .016" REMAINING THICKNESS IS .24" AND IS FOUND TO BE OUT OF LIMITS IAW B737-900ER SRM 53-00-53-1A-2.4.A.(2). REMOVED AND REPLACED FWD PIT L/H TRANSITION PANEL STA 500J+10 TO 500L IAW B737-900ER SRM 53-00-53-2R-5.