BERLIN (AP) — German military divers are working to hoist the wreck of a Stuka dive bomber from the floor of the Baltic Sea, a rare example of the plane that once wreaked havoc over Europe as part of the Nazis' war machine.

The single-engine monoplane carried sirens that produced a distinctive and terrifying screaming sound as it dove vertically to release its bombs or strafe targets with its machine guns. There are only two complete Stukas still around.

The Stuka wreck, first discovered in the 1990s when a fisherman's nets snagged on it, lies about 10 kilometers (6 miles) off the coast of the German Baltic island of Ruegen, in about 18 meters (60 feet) of water.

The divers have been working over the past week to prepare the bomber to be hoisted to the surface, using fire hoses to carefully free it from the sand. They have already brought up smaller pieces and also hauled up its motor over the weekend.

They are now working to free the main 9-meter (30-foot) fuselage piece and expect to bring it up on Tuesday, depending on the weather, said Capt. Sebastian Bangert, a spokesman from the German Military Historical Museum in Dresden, which is running the recovery operation.

Initial reports are that it is in good condition despite having spent the last seven decades at the bottom of the sea, he said.

"From my perspective there's a lot of damage — it's been under water for 70 years — but our restoration crew says it's in really good condition for being restored," said Bangert, speaking from the deck of the Navy ship being used for the operation. "That's our goal — a complete restoration and not conservation as a wreck."

So far, little is known about this particular plane — when it crashed, who its pilot and gunner were and whether they survived the crash, Bangert said. Once the plane is brought to the surface, researchers will use the serial number to track down all of the information.

The Junkers JU87 — known by most as the Stuka, which is short for the German word for dive bomber 'Sturzkampfflugzeug" — first saw service in the 1936-1939 Spanish Civil War, being sent by Hitler to help the fascists.

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The only two known complete Stukas are on display at the Royal Air Force Museum in London and at the Museum of Science and Industry in Chicago. Both are later models. Bangert said from the motor, the one just found is also likely a later model "JU87D."

Still, to find such a complete example is "terrific," said Andrew Simpson, curator of the aircraft collection at the RAF Museum.

"You are still talking about less than a dozen in the world, even if you include every back end and center section found on the Russian steppes," he said. "Any Stuka is good."

Following its service in Spain, Stukas fired the first shots of World War II, dropping Nazi bombs on the Polish town of Wielun on Sept. 1, 1939, killing some 1,200 civilians in what is considered one of the first terror bombings in history.

German ace Hans-Ulrich Rudel claimed to have destroyed more than 500 tanks, mostly on the Eastern Front, and several ships including a Soviet battleship, primarily in the Stuka.

The Stuka was used throughout the World War II, but for all its successes in the early days on the Western Front and in the later invasion of the Soviet Union, the aircraft was later overmatched by quicker and more maneuverable Allied fighter planes.

As museum pieces today, they're a big draw for visitors and also important for researchers and historians, said Kathleen McCarthy, director of collections at Chicago's Museum of Science and Industry, whose Stuka had been shot down over Libya in the last year of the war.

"The discovery and raising of a third Stuka from the sea floor will be a great asset for both scholars and the general public interested in learning more about historic military technology as well as this critical period in our world history," she said.

The German Military Historical Museum plans to eventually display the Stuka at its Air Force Museum, located at the former Gatow airport in Berlin.