Update, 10:12 a.m.: All lanes of Interstate 83 southbound have reopened, according to the Maryland Department of Transportation.
Previous: Interstate 83 southbound is partially closed just south of the Maryland border Thursday morning.
As of 9:10 a.m., one lane of I-83 southbound was open in Baltimore County, and officials were reporting traffic was backed up to Shrewsbury, Exit 4 in Pennsylvania.
A nine-vehicle crash at 5:45 a.m. stopped traffic at the York Road exit, exit 33, according to the Maryland Department of Transportation.
Check back later for more information.