Power lines fell down on Interstate 270 in Clarksburg, Maryland, shutting down all lanes at the start of the Monday evening rush.
Maryland State Police said all lanes of I-270 have reopened in both directions at the Frederick County/Montgomery County line, but there were significant delays for some time after the lanes reopened.
Crews had to clear live wires tht fell across the roadway. There were also reports of downed trees in that area of I-270.
Severe weather moved through the area and a tornado warning was in effect for Montgomery, Frederick and Howard counties for a short time.
Stay with News4 and NBCWashington.com for updates to this developing story.