The National 9/11 Pentagon Memorial will close soon for several months of repairs.
The work, which includes lighting repairs and construction, is expected to be finished in late May 2020, according to a release sent Monday by the U.S. Department of Defense.
The first phase of closures is set to begin Monday, when the memorial bench area will close. Then the Memorial Gateway entrance of the memorial will close Nov. 16.
The lighting systems in the pools under the memorial benches have been failing due to water seeping into the fixtures, officials said. The project will fix that problem and will also replace the memorial's entire electrical system, including all the bench lighting.
"We are aware of the impact that this closure will have on family members and visitors to the Pentagon Memorial," officials said in the release. "Every effort has been made to develop a construction plan that will enable the work to be completed in a quick and efficient manner, reducing site closure time."
The memorial, which was dedicated Sept. 11, 2008, is normally open 24 hours a day and seven days a week.
The Pentagon Chapel will not be affected by the project, officials said.