Crews battled a natural gas leak Thursday morning in Johnston just south of I-80/35.
The call came in at about 8:30 a.m. at a town border station off Lower Beaver Road where a Northern Natural Gas pipe connects with MidAmerican Energy.
Officials say crews were working on a pressure relief valve when it blew.
A witness described the noise as sounding like a jet engine.
Traffic was blocked around the vicinity on Skyline and Oaklyn drives to avoid the risk of a spark igniting the gas.
There are no reports of injuries and crews had the leak under control within half an hour.