WASHINGTON — Montgomery County fire crews are investigating an arcing insulator at the Bethesda Metro station on the Red Line. Metro maintenance crews are also on the scene and have shut down power. Trains are single tracking on the Red Line but there is no fire emergency, officials say.

U/D – Bethesda Metro – arcing insulator, Metro maintenance crew on scene, power shut down, trains single tracking, no fire emergency

— Pete Piringer (@mcfrsPIO) May 17, 2015