The left lane of northbound U.S. Highway 85 in Commerce City will be closed for several hours Monday evening after a motorcycle crash caused by a piece of metal that fell from a bridge, police said

At about 2:38 p.m., a semi driver stopped abruptly when the piece of metal fell to the road, causing a Dodge Ram pickup following behind to do the same, police said.

A motorcycle rider slammed into the back of the pickup. The rider was rushed to a local hospital, but a name and condition were not available Monday evening.

Commerce City police said Burlington Northern Railroad owns the bridge. The rail company and Colorado Department of Transportation are inspecting the bridge .

One northbound lane on U.S. Highway 85 and both southbound lanes remain open.