There are cracks in the World War II Memorial on the National Mall, and they’re getting bigger. They include a 20-foot-long “hairline fracture” in one of the main pillars in the Atlantic section of the memorial, as well as smaller cracks in the D.C. pillar, NBC Washington reports.

It’s possible that the crack has been at the Memorial “since the monument’s construction, as it appeared shortly thereafter,” National Park Service spokesperson Mike Litterst tells DCist. The memorial was dedicated in 2004. “But it has gotten worse in recent years.”

That may explain why the crack recently caught the eye of the U.S. House Committee on Appropriations, which mentioned it in a report released this week on funding for the Department of the Interior for fiscal year 2020. “The Committee is concerned that the proposed operations plan does not address a hairline fracture in the Atlantic side of the memorial,” the report states. “This fracture requires immediate attention before further damage leads to increased repair costs.”

The National Park Service says that the crack isn’t an immediate danger to visitors. “The memorial remains structurally sound and the cracks pose no threat to public safety,” Litterst said in a statement.

The Memorial receives about 5 million visitors every year, according to the Congressional report. And it will likely see higher traffic soon: over the next few weeks, it will host a series of public events commemorating Memorial Day this weekend and the 75th anniversary of D-Day in early June.

NPS’s next step will be performing a study to understand why the crack appeared and what fixes will be required, according to Litterst. “The process and timeline for the repairs will be determined following the completion of the structural assessment,” he says.

The WWII Memorial is far from the only monument on the National Mall in need of repair these days. A 2018 report from the Pew Charitable Trusts includes an extensive list of deferred maintenance, which had an estimated cost of $840.3 million in fiscal year 2015. “Key projects include repairing the roofs of the Jefferson and Lincoln memorials. Initial work to prevent pieces of the Jefferson Memorial from falling on visitors has been completed, but longer-term repairs are required,” the report found. It also references a crumbling 5-mile long sea wall along East Potomac Park, and flooding damage to sidewalks along West Potomac Park, the Tidal Basin, and the Jefferson Memorial.

But the WWII Memorial has its own endowment for repairs and preservation, which was set up when the monument was dedicated in 2004, Litterst told NBC, so it won’t be competing for funding with other projects.

Congressional testimony from a National Park Service official in 2012 indicates that, several years ago, the WWII Memorial also underwent repairs to parts of its concrete slurry wall, which is part of the foundation that prevents groundwater from seeping underneath the monument.