Someone stole four memorial plaques for Navy seamen killed in World War II from the USS Ling submarine on the Hackensack River and then flooded the museum, said authorities who were trying to find them.

A caretaker at the River Street museum and memorial summoned police, who found that someone "entered the USS Ling and purposely and forcefully opened numerous hatches throughout the submarine, causing the entire interior of the submarine to flood with river water," Police Capt. Brian Corcoran said.

Taken were four bronze plaques, valued at $10,000, honoring 52 submarines lost in the Second World War, Corcoran said.

"The Hackensack Police Department’s Detective Bureau is investigating this disgraceful incident further, with hopes to locate and prosecute those responsible," the captain said.

Museum officials Leslie Altschuler and Jack Brown noticed that some of the deck guns were out of place and hatches open when they arrived Tuesday.

"This is terrible," said Altschuler, the base commander. "It's a memorial."

The submarine came to Hackensack in 1973 from Brooklyn, where it had been used for Naval Reserve training.

Brown and Altschuler both trained on the boat in the 1960s.

The museum was recently evicted from the property behind the Heritage Diner due to the construction of new housing units next door at the former site of the Bergen Record newspaper.

All of the records and artifacts were supposed to go but the submarine was to remain, they said.

"We don't know how bad the damage is until water gets pumped out," Altschuler said. "It might not be salvageable anymore."