More than 60% of U.S. fuel pipelines were built before 1970, according to federal figures. Recent disruptions on Colonial Pipeline Co.’s fuel artery running up the East Coast show why some energy observers worry that this is a problem.

The pipeline, which began operating fully in 1964, was partially shut down for nearly two weeks in September. Fuel prices spiked throughout the Southeast, rising more than 20 cents a gallon in places like Atlanta.

Motorists this week began to worry again after the company’s main gasoline pipeline, which supplies about a third of the gas consumed on the East Coast, was shut down. It was struck by construction equipment Monday, killing one person and injuring several others.

The company has said the 5,500-mile pipeline, which runs from Houston to New Jersey and serves 13 states, could restart as soon as Saturday, though as of Wednesday afternoon the pipeline was still on fire. Gasoline futures fell 2.4%, to $1.4479 a gallon, on the New York Mercantile Exchange Wednesday after rising as much as 15% following the Colonial explosion.

Colonial isn’t the only major pipeline constructed decades ago. That includes a 3,000-mile fuel pipeline that first opened in 1956 and serves California, Texas and five other states. Another system that now carries fuel more than 1,800 miles from the Gulf Coast to the Chicago area opened in 1971.