UGI UTILITIES, INC

Incident Narrative

ON FEBRUARY 9TH, AN EXPLOSION OCCURRED AT N. 13TH AND W. ALLEN STREETS IN ALLENTOWN, PA. DESTROYING 544 AND 542 N. 13TH STREET RESIDENCES. SUBSEQUENT FIRE DAMAGE DESTROYED (6) ADDITIONAL ROW HOMES, 530-540. THE LIKELY SOURCE OF THE GAS IGNITED IN THE EXPLOSION WAS A CIRCUMFERENTIAL SEPARATION/FRACTURE ON A 12"" CAST IRON MAIN LOCATED ON W. ALLEN STREET. GAS FROM THE CRACK APPEARS TO HAVE MIGRATED TO 544 N. 13TH STREET AND IGNITED.. ** IN PART D #2E DOES NOT INCLUDE ""'CONFIDENTIAL SETTLEMENTS"" RELATED TO PERSONAL INJURY OR WRONGFUL DEATH CLAIMS. 12/15/2017 SUPPLEMENTAL REPORT SUBMITTED TO UPDATE THE FOLLOWING: NCR REPORT NUMBER CORRECTED. THE CAST IRON PIPE THAT FAILED WAS REPLACED WITH POLYETHYLENE PIPE AND THE SYSTEM WAS RESTARTED ON 3/11/2011. THE CAST IRON PIPE FAILED DUE TO A COMBINATION OF FACTORS. FROST AND FROZEN GROUND LIKELY CRACKED THE ROAD SURFACE. THE COMPROMISED ROAD SURFACE, AND FROZEN GROUND, ALLOWED VEHICULAR TRAFFIC LOADS TO BE TRANSFERRED TO THE PIPE WHICH EVENTUALLY CAUSED CRACKING IN A PARTIALLY GRAPHITIZED SECTION OF THE MAIN. MATERIALS ANALYSIS INDICATES THAT ABSENT THE CONFLUENCE OF THE FROST HEAVE AND EXTERNAL LOADING, THE PIPE LIKELY WOULD NOT HAVE OTHERWISE FRACTURED..