UPDATE, 9:36 p.m.: A man riding a bicycle was killed on the C&O Canal Towpath in Montgomery County Sunday night when he was struck by a falling tree during the storm, authorities said. The man was not identified.

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Post reader Michael Hutshneker snapped this photo of a downed tree at the 1500 block of P Street NW. (User-submitted)

ORIGINAL POST, 7:47 p.m.:

A spectacular thunderstorm, with torrents of rain, high winds and flashes of lightning swept across the Washington area Sunday evening, toppling trees, knocking out power to 40,000 homes and businesses, and clearing the National Mall of visitors and tourists.


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ALSO: Lightning strike injures 5 Gettysburg reenactors

People are evacuated from the West Lawn of the U.S. Capitol. (Keith Stefanelli/User-submitted)

At one point during the evening, Dominion Power reported about 20,000 outages in Northern Virginia and Pepco said about 15,000 of its customers in the District and Maryland had lost power. Thousands more homes and businesses served by BG&E also were without electricity for a time.

Indications were late Sunday that at least one more round of storms was likely to drench the area before conditions settled down. The evening storms followed an early morning electrical storm that brought heavy rain to parts of the region.

The view from Dupont Circle

Rehearsal audience for A Capitol Fourth takes cover

Another look at the gusts and rain