Drying soil may have shifted, causing a water main to break Monday in Ashdown, Ark., Water Superintendent Jason Tomlinson said.
Crews worked about five hours to replace 8-inch and 6-inch water lines near Locust Street and South Smith Circle.
Tomlinson estimated the pipe was installed in the 1930s.
"We waited until the afternoon to not interrupt school," he said.
"It was not a big deal. When weather dries it can cause the ground to shift and the old main lines made of metal can pop," Tomlinson said.
"It amazes me how the soil can shift," he said.
"We have professional operators certified by the department of health and the Arkansas Department of Environmental Quality and they worked fast," he said.