About 3:48 p.m. a recycling company employee detected the odour of gasoline at the site of a closed landfill. He investigated and found gasoline flowing up through the ground in the vicinity of a 40-inch-diameter steel pipeline that ran through the landfill. The employee called the numbers shown on a nearby pipeline marker and reported gasoline on the ground. About 15 to 20 minutes later, an employee confirmed the leak by on-site inspection and requested that the pipeline control centre shut down the line. The rupture resulted in the release of more than 113 m³ of gasoline, about 64 m³ of which were eventually recovered. No alarms were detected in the control centre to signify that the line had failed. By September 1998, costs of cleanup efforts and repair to the pipeline exceeded $3.2 million.

The 8 mm wall-thickness welded steel pipe was constructed at a depth of 1.2 m through the then-active, county-owned landfill in 1978. The section of the landfill where the pipeline was located remained in use until about 1980, during which time additional debris was placed over the pipeline. The landfill was officially closed in 1987. At the time of the accident, about 2 to 3 m of debris and earth covered the pipeline at the point of failure.

The National Transportation Safety Board (US NTSB) determined that the probable cause of the pipeline rupture was settlement of soil and compacted trash underneath the pipeline, which resulted from the failure of the Pipeline Company to take effective steps during construction to adequately support the pipeline. Contributing to the pipeline failure were the activities of a Recycling Centre, which subjected the pipeline to additional stresses at and near the site of the rupture, and the failure of the aerial patrols to report to the company that recycling activities were ongoing on the pipeline right-of-way.

After the accident, the company changed its telephone reporting system: all calls to the line are routed to an automated response system where callers are asked to press 1 if they are calling to report a leak or accident. These calls are directed to the pipeline control centre. Callers who call for other, non-emergency, reasons are referred to another number and asked to call during regular business hours. Callers who call from a rotary phone or who hold the line without making a selection are automatically directed to the pipeline control centre.