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At 4:45 p.m., central standard time, Aprif 1fi, 1980, gasoline at the Williams Pipe Line Company's Minneapolis terminal in Roseville, Minnesota, sprayed from the fractured cast-iron base of a station booster pump at 72 psig pressure, vaporized, and exploded after it was ignited by the arcing of an electric switch in the mainline pump control room 50 feet downwind of the booster pump. The resulting fire bumed for 2 days, fueled by gaso[ine and fuel oil leaking from ma�y burned-out flange gaskets, f�om drainage from hundreds of feet of pipe connecting 37 tanks, and from the receiving and loading manifolds. The explosion killed one person. The fire injured three persons and destroyed the receiving manifold piping and valves, pumping equipment, and four vehicles. About 3,500 barreis (147,000 gallons) of petrofeum products bumed and property damage was estimated at $3 million. The National Transportation Safety Board determined that the probable cause of the accident was fhe fracture of the base of a 30-year-old cas#-iron pump which had not been hydrostatically tested at its new instaflation. The failure ailowed gasoline under pressure to spray, vaporize, and enter an electric switchgear building 50 feet away. Ignition occurred from an efectfic arc produced by opening a switch. Contributing to #he accident was the failure of the company to (1) use expfosson-proof equipment in a potentially hazardous vapor area, and {2) fiEl the gap between the pump and its foundation with grout. ln Mounds View (from NTSB Repo�t NTSBIPAR-87J02): About 4:20 a.m., on July 8, 1986, line 2N, an 8-inch products pipeline at Mounds View, Minnesota, operated by Williams Pipe Line Company ruptured. Unleaded gasoline under a pressure of i, 434 psig spewed from a 7-1/2 foot-long opening along the longitudinal seam of the pipe. Vaporized gasoline, combined with air and liquid gasoline, flowed along neighborhood streets. About 20 minutes later, ihe gasoline vapor was ignited when an automobile entered the area. Following an expiosion-like noise, fire spread rapidly along the path of the liquid gasoline. Two persons were burned severely and later died, and one person suffered serious burns_ There was substantial property damage and soi! and water pollution. The National Transportation Safety Board determined that the probable cause of the rupture at Mounds View, Minnesota, was the faiture of Williams Pipe Line Company to correct known deficiencies in the cathodic protection appEied to the firsi 10 miles of line 2N. Contributing to the failure of the pipeline was the susceptibility of the low frequency, electric resistance welded pipe to weld seam corrosion and the Department of Transportation's ineffective inspection and enforcement program. Contributing to the extent of the damages was the failure of the pipeline company to provide adequate direction, through its procedures and training, for its employees to respond effectively 2-4