WASHINGTON (AA)  Motorists were stranded across parts of the wider Washington, D.C. metropolitan area as roadways were inundated by sheets of heavy rain during Monday’s rush-hour commute. The storms moved through parts of the nation’s capital, Maryland and Virginia resulting in mass flooding that left major thoroughfares in disarray, and which seeped into at least one underground metro station, causing delays.

One flash flood hit Canal Road, a major traffic artery into the nation’s capital along the Potomac River, with photos posted to social media depicting commuters standing atop their vehicles waiting for rescue. Multiple car crashes were reported in the region. Amtrak, the nation’s largest railroad service, halted service south of Washington, D.C. due to the harsh conditions.

“Service Disruption: Trains traveling south of Washington are now stopped due to severe weather conditions. We will update as more information becomes available,” Amtrak wrote on Twitter. It later posted several updates for specific trains that had been halted en route to their destinations.

Flight traffic appeared relatively undisturbed at Reagan National Airport in northern Virginia, however. The FlightAware website tracked no delays and eight cancellations, but it is unclear if the cancellations were weather-related.

Minor flooding was also reported in the White House basement. It has since been largely remedied.