An Australian Navy ship on Monday located a United States military aircraft that had crashed off the Queensland coast, AP reported. Three missing US Marines are feared dead.

“Shortly after commencing survey operations in the area, the submerged aircraft was located,” Australian Defence Minister Marise Payne said in a statement, adding that the underwater search operations will begin soon to look for the bodies of the marines.

The MV-22 Osprey had submerged in the Shoalwater Bay on Saturday during a military exercise, and 23 people had been rescued. The tilt-rotor aircraft looks like a conventional plane, but can take off vertically without a runway with the help of its helicopter-like rotor blades.

The US Marine Corps said they were investigating the accident.