The Coast Guard suspended its search for three missing mariners Monday after two towboats collided on the Mississippi River at mile marker 123, near Luling, La., Sunday.

Coast Guard Sector New Orleans received a report early Sunday morning that the 69'x30'x10' towboat RC Creppel and the 186'x54'x10' linehaul towing vessel Cooperative Spirit collided near New Orleans. Four members of the RC Creppel went missing. One crewmember was later rescued.

Coast Guard crews searched over 835 nautical miles for approximately 67 hours but were unable to find the three missing mariners. The accident occurred when the Cooperative Spirit was transiting upbound on the river when it entered a barge fleeting area and allided with barges before colliding with the RC Creppel and sinking it. Built in 1975, Cooperative Spirit is owned by American River Transportation Company (ARTCO), a wholly owned subsidiary of Archer Daniels Midland (ADM). RC Creppel, built in 2012, is operated by Elite Towing.

“This is a complex response that has a search-and-rescue component, as well as a pollution component that will require planning and coordination to execute,” commanding officer of Sector New Orleans Capt. Kristi Luttrell, said in a statement following the accident.

The RC Creppel was pushing two barges carrying sulfuric acid, one of which was damaged in the incident and reportedly released an unknown amount of vapor into the air, when the accident occurred. The source of the release was secured Sunday.

While the search for the missing has been suspended, air monitoring is ongoing in the area surrounding the incident. The air in the immediate vicinity of the affected barge has now been cleared of any traces of sulfuric acid, the Coast Guard said. There are no immediate health issues or concerns to the surrounding communities.

The Mississippi River reopened Monday night at 9:30 p.m. to vessel traffic from mile marker 121 to 123. However, the area is still subject to restrictions put in place by Coast Guard Sector New Orleans’ Vessel Traffic Service.

McKinney Salvage has been contracted to carry out salvage operations of the affected barge. Air monitoring in the area will continue until the salvage operations of the affected barge are complete.

The National Transportation Safety Board has joined the Coast Guard to investigate the cause of the incident.

Entities involved in the response include Coast Guard Air Station New Orleans, Coast Guard Station New Orleans, Coast Guard cutter Sailfish, Port of South Louisiana, St. Charles Parish Sheriff's Office, Louisiana Department of Fish and Wildlife, and St. Charles Parish Homeland Security and Emergency Preparedness Center.