Two barges that broke loose on the swollen Arkansas River have struck a dam in Oklahoma, and at least one sank into the river.

Muskogee County Emergency Management spokeswoman Tricia Germany says the barges were carrying a total of about 3,800 pounds of fertilizer. Germany says the concern was that the barges would block the water flow through the dam, but said the water initially appeared to be flowing well.

The barges have been floating out of control, on and off again, since Wednesday night near the town of Webbers Falls. Aerial footage from the Oklahoma City television station KFOR showed the moment of impact shortly before noon Thursday.

Officials had issued a mandatory evacuation order because of flooding concerns Wednesday night for the 600 residents of the town, which is located about 70 miles (113 kilometers) southeast of Tulsa.

Over Memorial Day weekend in 2002, a barge struck the Interstate 40 bridge pier at Webbers Falls, causing part of the bridge to collapse into the Arkansas River. Fourteen people died after their vehicles plunged into the water.

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