UPDATE: The scene was cleared early Tuesday evening

CHICAGO (CBS) — Several streets in the Loop were shut down Tuesday afternoon, after construction crews ruptured an underground gas main.

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According to the Fire Department, construction crews hit an unused gas main at State and Randolph streets around 12:30 p.m. Tuesday.

Scott Alwen from Peoples Gas said there was a small ignition that created pressure and a sound of an explosion. The gas line extends down State Street, and firefighters were blowing air through the abandoned main in order to prevent further ignition. Crews also checked the subways and nearby buildings to ensure they were safe.

One witness said that it sounded similar to a semi-truck applying its air brakes, but louder.

A few yards from where it happened, it made pedestrians run. And Nellie Hernandez and her co-worker at a store at State and Madison got a little anxious.

“We did lock the door. We did panic when we started to hear people running. Just because you don’t know what it is, you know.”

And she says – because what happened in Orlando was on her mind.

State Street was closed between Lake and Adams streets. Portions of Randolph, Washington, and Madison also were closed near State Street.

Traffic piles up at State and Wacker after a gas leak in the Loop. (Credit; Wendy Widom/CBS)

Traffic piles up at State and Wacker after a gas leak in the Loop. (Credit; Wendy Widom/CBS)

No injuries were reported, but traffic was tied up all around the Loop.

The CTA says the #6, #10, #29, #36, #62, #146, #147, #151 buses were temporarily rerouted in both directions near the Loop.

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