Narrative:

Before takeoff, a cabin attendant called and said she could see light at the rear galley door. I said that was ok as the doors did not seal till we were pressurized. We took off. About 4000 ft the flow light came on. The aircraft was light with 18 passenger. The aircraft was climbing 4000 FPM. At 15000 ft we leveled off and the cabin altitude was 8000 ft and climbing. I sent the first officer to investigate. He said he could see light from under the rear galley door. We told nyc that we were returning to lga with a pressurization problem. We returned to lga and made a normal landing. The mechanic said the door seal was torn.

Related reports:

Google
 

Original NASA ASRS Text

Title: AN ACR MD80 FLC DEPART WITH A GAP IN THE REAR GALLEY DOOR SEAL. LATER, THEY RETURN WHEN THE ACFT DID NOT PRESSURIZE.

Narrative: BEFORE TKOF, A CABIN ATTENDANT CALLED AND SAID SHE COULD SEE LIGHT AT THE REAR GALLEY DOOR. I SAID THAT WAS OK AS THE DOORS DID NOT SEAL TILL WE WERE PRESSURIZED. WE TOOK OFF. ABOUT 4000 FT THE FLOW LIGHT CAME ON. THE ACFT WAS LIGHT WITH 18 PAX. THE ACFT WAS CLBING 4000 FPM. AT 15000 FT WE LEVELED OFF AND THE CABIN ALT WAS 8000 FT AND CLBING. I SENT THE FO TO INVESTIGATE. HE SAID HE COULD SEE LIGHT FROM UNDER THE REAR GALLEY DOOR. WE TOLD NYC THAT WE WERE RETURNING TO LGA WITH A PRESSURIZATION PROB. WE RETURNED TO LGA AND MADE A NORMAL LNDG. THE MECH SAID THE DOOR SEAL WAS TORN.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.