Update July 6 at 12:10 p.m.
Freight service has resumed in one direction along the Union Pacific rail line.
Union Pacific crews worked through the night clearing debris from the in Northbrook after a freight train derailed en route to Wisconsin. Traffic on Shermer won't reopen until the bridge is rebuilt.
Traffic will reopen "after the bridge is done and there’s really no time line on that yet," said Mark Davis, a Union Pacific spokesman at the scene.
According to Davis, the cause of the derailment is still under investigation, but the collapse occured after 31 derailed train cars piled on the bridge.
The railroad company anticipates clean-up to finish by Thursday night, but they will still have to fill a crevice formed during the collapse and build a new bridge for the freight line.
"We don’t have a time table yet, on reconstructing the bridge, because we have to design it," Davis said. Union Pacific will construct the new bridge and they have started designing it.
This this is not the first derailment in the area, but according to Davis it is the first bridge collapse.
"To my knowledge it hasn’t fallen," the spokesman said. "[There was construction] about two years ago, but what they did was the concrete abutment, they didn’t do the bridge itself just the concrete."
Abutments are points in a bridge where two structures meet. Those were fixed in 2009 when two freight trains struck eachother at the same location.