FRANKENLUST TOWNSHIP, Mich. -- Bay County Central dispatch sent emergency responders to the M-84 overpass at Interstate 75 to investigate reports of falling debris Tuesday morning.

Several motorists contacted 911 around 10:30 a.m. to report chunks of concrete blocking I-75 southbound lanes.

There are no reports of injuries or damage to vehicles at this time, but southbound traffic was backed up for miles.

Bay County Sheriff John Miller said his biggest concern is the safety of Mid-Michigan drivers.

"MDOT is going check the roadway and make sure everything is safe," Miller said. "I'm sure they will be able to make repairs to it."

Southbound I-75 is down to one lane and could remain closed until Wednesday morning while crews inspect and repair the damage.

M-84 is also known as West Side Saginaw Road.