Executive Summary
About 1038 local time on January 16, 2019, the workboat MSRC 8-1 , which operated from the oil spill response vessel (OSRV) Louisiana Responder, capsized during an oil spill boom deployment exercise in the Lower Mississippi River near Boothville, Louisiana (mile 18), trapping both of its crew inside. While the OSRV’s crew and the US Coast Guard worked to rescue the trapped MSRC 8-1 crew, the boat sank. One crewmember died in the sinking; the other crewmember was not found and is presumed dead. The MSRC 8-1 was declared a constructive total loss with damage estimated at $250,000. A sheen of oil was sighted on the water after the vessel sank; no other pollution was reported.
Probable Cause
The National Transportation Safety Board determines the probable cause of the capsizing of the workboat MSRC 8-1 was the boat becoming perpendicular to a strong river current, for an undetermined reason, while tethered to the oil spill response vessel Louisiana Responder. Contributing to the accident was the unforeseen risk associated with conducting the exercise in a strong current, which also contributed to the severity of the outcome by hampering rescue efforts.
Report is relatively lengthy - 18 pages.
The company determined that the “taut towline while workboat was broadside to
the current tripped and capsized the boat.”