ASHEVILLE, N.C. (AP) -- Preliminary findings by a utility have determined a natural gas line ruptured near Asheville earlier this month because it was weakened when some of the metal was scraped off the pipe more than a decade ago.
The Jan. 10 explosion sent flames more than 100 feet high. No one was hurt.
PSNC Energy told the Citizen-Times of Asheville (http://avlne.ws/1bpE6x4 ) that a boring machine damaged the pipe in 2003. While the pipe wasn't ruptured, the machine did scrape metal from it.
Investigators haven't determined what ignited the gas, but in other explosions, the friction of gas escaping from a pipe is enough to create a spark.
The pipe was inspected for leaks twice a year, but its structure wasn't checked.
The North Carolina Utilities Commission is doing its own investigation.