Tourists rush to the Lincoln Memorial to take cover from Sunday’s storm. (Kevin Ambrose)

A bright afternoon sky transformed into a blinding downpour of rain in less than a minute Sunday, which sent tourists scurrying for cover. Some didn’t do the smart thing.

While many ran or walked for cover in buildings such as the Lincoln Memorial, some tourists huddled under large trees near the Reflecting Pool. This is never a good idea because lightning will often strike trees.

Suddenly, a bolt of lightning struck nearby, probably just west of the Potomac River near Rosslyn.  The thunder boomed across the Mall with a loud bang.  The lightning struck less than a mile away.

Tourists rush for cover during the thunderstorm Sunday afternoon, while some tour groups continued their tours under umbrellas. (Kevin Ambrose)

More lightning was well south of D.C., which produced long, low rumbles of thunder across the Mall.  The periodic rumbles of thunder lasted for about 20 minutes.  Those distant lightning strikes were probably three to five miles away.  Fortunately, no lightning strikes occurred on the Mall.

As the storm moved east, tourists emerged from cover, many thoroughly soaked.  Tour groups reassembled and continued their tours under umbrellas.  Activities on the Mall resumed but were dampened by the storm.

It’s important to note that if you’re surprised by a thunderstorm and caught outdoors in the open, it’s always best to find cover in an automobile or building as soon as possible.

Try to walk on paved surfaces and stay away from tall trees.  Never huddle under trees!

“Being underneath a tree is the second leading cause of lightning casualties,” the National Weather Service says.

The scenario described above repeats itself many times each summer on the Mall with fast-moving thunderstorms.  Fortunately, tourists are rarely struck by lightning in D.C., but the risk of a tragedy looms if lightning safety practices are not adhered to.

(Here are some important lightning safety tips from the National Weather Service: Outdoor lightning safety)

More storm photos …

A bike rider in the storm. (Kevin Ambrose)

A family walks up the steps of the Lincoln Memorial during the height of the thunderstorm. (Kevin Ambrose)

A tour group with umbrellas walks near the Reflecting Pool as the storm exits to the east. (Kevin Ambrose)