The fire started around 1 p.m. in the 1500 block of Morse Avenue. Authorities said the line was ruptured by equipment used by crews repairing the city's water system at the time. Ignition of the fire occurred due to static electricity build-up caused by the free-flowing gas.
Firefighters responded and contained the fire at the source. No injuries were reported.
Business along Morse Avenue between Market and Transport streets were briefly interrupted but remained open. Occupants in the businesses were advised to remain sheltered in place.