Update, 7:49 a.m.: 

All lanes of I-270 S have reopened at Shady Grove following a fatal accident. Residual delays are expected to continue. The cause of the accident remains under investigation.

Original post:

The main southbound lanes of I-270 after the Shady Grove exit are shut down this morning following a singe-vehicle accident this morning.

Local lanes are all open and drivers are being asked to use them instead.

No information was immediately available about the cause of the accident. Delays are expected to continue indefinitely until the crash is cleared.