A Maryland State Police Medevac chopper is headed to the scene of a major accident along northbound Interstate 95.

The crash took place at around 9:30 a.m. on Wednesday morning just below the Baltimore/Harford County line just prior to the Mountain Road exit, according to the Joppa-Magnolia Volunteer Fire Company.

One vehicle overturned in the crash and at least one person was critically injured.

All northbound lanes of I-95 are now shut down.

Motorists should expect heavy delays in the area.