What was found
CABIN HIGH ALTITUDE LIGHT ILLUMINATE AFTER REACHING FL 370. ON LEVEL OFF DURING ACCELERATION, CABIN HIGH ALTITUDE LIGHT ILLUMINATED. DONNED OXYGEN MASKS, DEPLOYED PAX MASKS AND COMPLETED CHECKLIST ITEMS. REFERRED TO CHECKLIST, ELECTED TO DECEND. PERFORMED CABIN ALTITUDE EMERGENCY CHECKLIST AND STARTED AN EMERGENCY DESCENT. HIGHEST INDICATION OBSERVED ON CABIN ALTITUDE ALTIMETER WAS 10,500 FT WITH A 2,000 FPM CLIMB INDICATION. ON REACHING 10,000 FT, RESUMED NORMAL COMMUNICATIONS THROUGH BOOM MICS. CONTINUED WITH NORMAL CHECKLISTS AND MADE AN UNEVENTFUL LANDING.