Two unmanned barges that broke loose on the swollen Arkansas River in Oklahoma crashed into a dam hours later and sank Thursday, and they didn't cause the structure to fail, which officials feared might happen. The barges carrying about 1,500 tons of phosphate fertilizer between them became unmoored Wednesday night in the Port of Muskogee, the AP reports, which sits at the confluence of the Arkansas and two other rivers and is about 40 miles southeast of Tulsa. At some point, the vessels were caught and secured to trees along the soggy riverbank, but they broke free again Thursday when the trees uprooted, said Tricia Germany of the Muskogee County Emergency Management Agency. The barges eventually crashed into the dam near Webbers Falls shortly before noon and quickly sank. "They did a direct hit, they kind of turned a little bit," Germany said.
Webbers Falls officials on Wednesday ordered the town's roughly 600 residents to evacuate due to the threat of flooding from the river, which is at 14 feet above flood stage. Later Wednesday, they sounded the alarm about the runaway barges on the town's Facebook page, warning they could hit the lock and dam: "If the dam breaks, it will be catastrophic!! Leave now!!" The lock and dam didn't break, though the Army Corps of Engineers was going to closely inspect them for damage, a state official said. Two downstream bridges, including an I-40 bridge, remained closed after the crash. If the warning about the runaway barges seems alarmist, it shouldn't: During Memorial Day weekend in 2002, a manned barge struck one of the I-40 bridge's supports, causing part of the bridge to collapse and killing 14 people whose vehicles plunged into the river. (A tornado caused heavy damage in Missouri's capital.)