UPDATE: MILWAUKEE (CBS 58) -- The Department of Transportation says all lanes of I-43 northbound near Walnut Street have been reopened.
The interstate was closed due to reports of shots fired.
The road was closed for nearly four hours.
MILWAUKEE (CBS 58) -- All northbound lanes of I-43 near Walnut were shut down Monday afternoon after reports of shots fired.
The initial report came in just before 2 p.m.
Acting Sheriff Richard Schmidt speaking out almost immediately after the lane closures.
"Shots fired on the freeway. It's untenable," said an impassioned Schmidt. "People's careless disregard for life. We have got to change the culture in Milwaukee County to where that type of nonsense has to stop."
Several hours into the investigation and there were no reports of anyone getting hit.
Deputies methodically walked along side each other up and down the interstate looking for evidence.
At least one evidence marker was place on scene.
As new information becomes available, we will bring it to you.