A Georgetown dispatch from colleague Ned Martel follows:

The crowd on the Wisconsin Avenue bridge materialized in minutes, out of nowhere, said police Lt. J.M. Hedgecock.

The British tourists and neighborhood residents with dogs on leashes were peering over the bridge railing, all eyes on a maroon mass of some kind, on the bed of the C&O Canal.

The silhouette looked curious, Hedgecock said. Was it a body lying on its side, wrapped in something like a blanket? The crowd stared as firefighters edged toward the bank of the canal. They prepared prods, tree cutters and ladders as they thought through the options.

“On the top, it looks like human hair,” Hedgecock said. There were seven emergency vehicles with lights blaring, blocking all traffic. Young British boys, high school age, were excitedly hypothesizing that the mass could be a bomb.

Finally, a lone firefighter descended to the canal bed. He lifted up the wet blanket and revealed what was underneath: a large orange safety cone.

It was as if a wet blanket fell upon the crowd. A New Zealand TV news crew decamped. The Brits broke into two camps in search of coffee and a warm, dry place. The passerby who alerted police and stood vigil on the bridge expressed relief. “All that ruckus for nothing,” said Ranit Mishori, who tugged on the leash of her dog, Pyke, and headed back home.