First the boat ramp to the USS Arizona Memorial was damaged and instead of disembarking onto the monument, visitors were limited to boat tours of the area.

Now the shoreside dock at the memorial’s visitor center is sinking, making it too risky for visitors to get onto the boats.

Harbor tours of the USS Arizona Memorial were halted Sunday because a 180-foot-long floating concrete shoreside dock partially sank overnight — making it impossible to embark people on boats at the visitor center, officials said.

The National Park Service said it is hopeful harbor boat tours can be resumed within a week.

The temporary loss of access to Navy launches is the second blow experienced by the National Park Service and the 4,000 to 5,000 visitors daily seeking to pay homage at the sunken Dec. 7, 1941, battleship grave for over 900 men killed on the day of infamy.

Walk-on access to the memorial that straddles the sunken ship was stopped on May 10 after park staff discovered that the 105-foot floating concrete pier that served as a boat landing had too much lateral movement and was pushing and pulling on the 4-ton, 30-foot metal bridge connecting the dock to the circa-1962 memorial.

The force was enough to shear off a stainless-steel attachment bolt on the memorial. Public access was curtailed as a fix was sought. A new anchoring system is planned with walk-on access expected to resume by this year’s anniversary of the Pearl Harbor attack, the park service said.

The inability to step foot on the walkway memorial is a disappointment for many who come from far and wide to recall the surprise Japanese attack that drew America into World War II.

Harbor boat tours that pass by the memorial and adjacent Battleship Missouri Memorial were put in place to allow some access to what used to be Battleship Row.

But with the partial sinking of the shoreside pier, the harbor access has been curtailed.

“The Pearl Harbor Visitor Center will still be open as usual from 7 a.m. to 5 p.m., and our museums, shoreside exhibits, and bookstore will be unaffected. Our partner sites will also be open as usual,” the World War II Valor in the Pacific National Monument, which includes the Arizona Memorial, said on its Facebook page.

Spokesman Jay Blount said that the shoreside dock, put in placed in 1999 and nearing the end of its life­span, has 10 separate but interconnected floating chambers. The two middle chambers have been taking on some water for months, with park crews pumping them out as needed.

“Something changed yesterday to where it began taking on water very quickly,” Blount said.

Park service staff and Navy personnel with Joint Base Pearl Harbor-Hickam attempted to mitigate the sinkage through the night as the waterlogged center cells started pulling down other segments, causing the dock to bow in the middle.

Crews were pumping out 150 gallons a minute and were not keeping up, Blount said. The water is 10 to 15 feet deep where the dock is now partially sunk, he said. No harbor tours were available today.

If given authorization, the Navy indicated it could return in a couple days to refloat and fix the shoreside dock — repairs that also could take a couple days, Blount said. That would allow boat harbor tours to resume.

“I really can’t highlight enough how helpful Joint Base has been,” Blount said.

Pacific Historic Parks, a nonprofit that supports the Arizona Memorial, is trying to raise $1.7 million to match the same amount in federal funding to replace the shoreside dock in 2019, officials said.

A new anchoring system is planned, meanwhile, for the concrete floating dock attached to the memorial itself. Blount said the hope is to have the dock operational by Thanksgiving, but a bigger goal is to have access by Dec. 7.

“We’re doing everything we can to have the memorial accessible by then,” he said.