UPDATE: Northbound US 23 open after bridge demolition

ANN ARBOR, MI -- Northbound U.S. 23 near Whitmore Lake will remain closed until work crews can tear down a severely damaged overpass.

Early Thursday, March 10, a semi-truck carrying a high load struck the 8 Mile bridge, causing significant damage to the bridge, said Kari Arend, a Michigan Department of Transportation spokeswoman.

Engineers determined the structure needs to come down, she said, and MDOT is working on getting an emergency contract in place to remove it.

MDOT does not have an estimate on when Northbound U.S. 23 will reopen, she said.

"We are trying to do this as quickly as possible," Arend said. "We are asking motorists to avoid the area, especially for the evening and morning rush. We do understand there will be traffic backups."

As of noon Thursday, northbound U.S. 23 was backed up to 6 Mile Road. Traffic was detouring on the exit and entrance ramps at 8 Mile Road in Northfield Township.

The 8 Mile Road bridge will remain closed for months during the tear-down and replacement.

Once the police investigation is complete, MDOT officials say they will make a claim with the responsible party's insurance company.

MDOT already had plans to replace the 8 Mile bridge, according to its list of 2016-2017 projects for U.S. 23.

The bridge scored a 32 out of 100 on sufficiency and had a "satisfactory" superstructure but a "poor" bridge deck. Its superstructure is in "serious" condition.

MDOT conducted repair work on the 8 Mile Road bridge in late 2010.

Lindsay Knake is a cops and courts reporter for The Ann Arbor News. Follow her on twitter or contact her at 989-372-2498 or lknake@mlive.com.