As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFT PIT DOOR SURROUND SILL WEB CORRODED BETWEEN STA 787+10 TO STA 847. GROUNDED - YES. BLENDED CORROSION ON AFT PIT DOOR SILL WEB FOUND TO BE OUT OF LIMITS IAW B737-900 SRM 53-60-15-1A-1 REMOVED AND REPLACED SILL WEB IAW B737-900 SRM 51-40-02-0G-0W=2.00 O=.050 R=.043 L=14.00 D=.007.