"monocacy" was at kiuklang protecting american neutrality during the japanese invasion of china, when on 29 august 1938 several mines exploded within of the ship, showering the gunboat with fragments. she was then held at the port until the japanese completed sweeping operations some days later. she was decommissioned at shanghai on 31 january 1939. the veteran gunboat was towed to sea and sunk 10 february 1939 in deep water off the china coast.