At 9:32am on January 10, 1976, gas which was leaking into the Pathfinder Hotel in Fremont, Nebraska, ignited. The gas was leaking from a 2 inch plastic pipe which had pulled out of its compression coupling; the gas seeped into the hotel becuase it had been capped above by frozen earth and a concrete road surface. The hotel exloded and fire ensued; the explosion and fire destroyed the hotel, damaged nearby buildings, and broke windows within a one block radius. 39 persons were injured and 20 persons were killed.
We determined that the probable cause of the accident was the contraction, due to cold temperatures, of a 2 inch polyethylene plastic main within a 4 inch casting. the contraction of the plastic main cuased the pope to pull ouut of the inadequately connected compression coupleing.
As a result of this investigation, we made the following safety recommendations
To the Nebraska Natural Gas Company:
- Review its entire system to see if pipe has pulled out of its coupling elsewhere and rectify any potentially hazardous conditions Found. (P-76-03)
- Conduct tests below the frost level during this review of the system to monitor all plastic pipe joints made with short compression couplings where pullout and resultant gas leaks could occur. (P-76-04)
- Use Manufacturures proprietary transition fittings, installed in accordance with written procedures, or use pip to casing anchors to limit contraction of Plastic Pipe, until a commpression coupling is verified by tests to be as strong as the plastic pipe being joined.(P-76-48)
- Develop written procedures and an inspection program to insure that all plastic pipe joints meet the design and installation provisions of 49 CFR 192(F) (P-76-49)
- Revise the company's written procedures to include the maximum length of plastic pipe to be used with compression couplings, the number of foot pounds of torque equired for each size of compression coupling, a time interval during constuction between retorquing of couplings and the type of stiffener to be used with each brand of coupling. (P-76-050)
- Develop written procedures to handle gas leak emergencies and evcuation, and instruct operating and maintenance employees as to their roles in carrying out these procedures. (P-76-051)
- Develop a procedure to shut down the sustem during emergencies. (P-76-052)
- Develop a mnethod of receiving emergency telephone calls in order to assure immediate response to emergencies. (P-76-053)
- Improve customer education program and liaison between the gas company, the police, and the Fire Departments. (P-76-054)
- Equip emergency vehicles with combustible gas leak detectors, distribution maps and other necessary tools. (P-76-055)
To the Department of Transportation:
- Study the plastic-to-steel transition nroblems and take appropriate regulatory action to correct any unsafe practices. (P-76-43)
- Revise 49 CFR 192 281(e) (2), 'Mechanical Joints," to require that stiffeners be designed to be compatible with compression couplings so that pipes cannot pull out of the couplings (P-76-44)
- Determine if there are locations or circumstances where standard compression couplings are unsafe, and amend 49 CTR 192 accordingly to prohibit their use for such applications. (P-76-45)
- Analyze the methods which operators use to receive and respond to emergency calls and, based upon this analysis, amend 49 CFR 192, "Operations, to specify minh acceptable standards (P-76-46)
- Amend 49 CFR 192, "Operations ," to require that operators record the receipt of emergency calls, the response to the calls, and the time of each significant action taken by the operator (P-76-47)
To the City of Fremont
- Reemphasize to city personnel who ar assinged to the emergency desk the importance of helping people who call in to report gas leaks and require personnel to furnish emergency gas company numbers to the public. (P-76-056)
- Coordinate emergency activities with the gas company and determine what responses should be made to various types of gas emergencies. (P-76-057)
