The Mississippi River was shut to all vessels Tuesday night after the Westchester, a 13,000-barrel crude oil spill near the mouth of the river some 60 miles south of New Orleans, the U.S. Coast Guard said. A Bahamian-flagged crude oil tanker ran aground near the mouth of the river close to Venice, La., around 6 p.m. CST Tuesday, Nov. 28, and spilled about 13,000 barrels of Nigerian sweet crude oil, said Petty Officer Joe Patton. The river had been shut between mile markers 9 and 38 (a nearly 30-mile stretch), Patton said. The Coast Guard and other federal agencies are assessing the extent of the spill. Containment booms and about 30 vessels are involved in the clean-up, Patton said. Refineries were reportedly unaffected, as the cargo was destined for a pipeline terminal.