Hardin, IL (KTRS) The U.S. Coast Guard is investigating what being is described as a “major marine casualty” after 3 tugboats sank on the Illinois River Friday.

The incident occurred in Calhoun county. The vessels were moored to a barge near Hardin, Illinois when they began taking on water. The tugboats were unoccupied, and were carrying close to 5000 gallons of diesel. The Coast Guard is working to contain the fuel so that it doesn’t make it’s way downstream.

An excavation crew is expected to arrive later this week to begin clearing the wreckage. No injuries have been reported.