Waterloo - Police and fire officials were called to the scene of a gas leak at the intersection of Williston and Hammond in Waterloo Thursday evening. The leak was reported at about 4:30 p.m. MidAmerican Energy officials on the scene shut off the flow to the leak at about 6:15 p.m.

The intersection is under construction and a contractor moving dirt struck a 4-inch gas main that was exposed by the project, said MidAmerican Energy spokeswoman Ann Thelen.

Although the hiss of escaping gas could be heard a block away from the rupture, no one was evacuated from the area. Light wind let the gas dissipate minimizing the threat, fire officials on the scene said.

"Natural gas is lighter than air," said Waterloo Fire Captain Steve Weliver. "As long as you don't have conditions that keeps it low to the ground, it's not an immediate threat."

No customers lost service because of the leak, Thelen said.