President Trump said on Saturday that “multiple individuals” had been arrested for vandalizing the Lincoln Memorial Reflecting Pool, and that problems with a more than $14 million renovation project had become so severe that the pool would likely have to be at least partly drained for “necessary repairs.”
The president’s announcement late Saturday, made on social media, was his starkest acknowledgment of the pool’s rapid deterioration in recent days. The water this week became covered by clouds of blooming algae, which were obscuring a floor that had just been painted a shade that Mr. Trump has called “American flag blue.” The paint then began to peel off, making it a tourist destination for unusual reasons.
Among those accused of vandalism was David Carter Hearn, 67, a cyclist and three-time Olympian as a canoeist who says he stopped at the site on Friday just to have a look, then reached down to touch a strip of peeling blue paint mixed with the algae.
The U.S. Park Police arrested Mr. Hearn shortly after, accusing him of destroying government property, a crime that can carry up to a 10-year prison sentence. Mr. Hearn denies the charge.
“I was just a curious, concerned citizen,” he said in an interview. “I guess I was there at the wrong place, wrong time.”
The administration has not released the names of others accused of vandalizing the pool, a crime that Mr. Trump said on Saturday could lead to “years in jail.” In a later post, he said without evidence that vandals had “poured corrosive and destructive chemicals into the Pool.”
The project, one of many Mr. Trump is undertaking around the capital as the United States nears its 250th birthday, has faced intense scrutiny, including from engineers and other experts who warned that the hastily undertaken project was unlikely to undo the problems that have plagued the pool for decades. A construction company tied to Mr. Trump was awarded a no-bid contract and painted the bottom of the pool.
Mr. Trump said on Saturday that he had met with contractors earlier in the day to discuss the state of the pool.
The Interior Department said this week that agency workers had “killed the algae” that had expanded with heat and humidity. But on Friday afternoon, the water was stained by clumps of algae where National Park Service staff members had scrubbed away bright green blooms along the bottom of the basin. The pool’s new coating was also missing large sections, including a gap roughly the size of a park bench. Underneath appeared to be the original concrete basin.
Mr. Hearn, of Bethesda, Md., said that he was on a 50-mile bike ride before stopping at the pool, and that Park Police officers detained him for more than four hours on Friday at a facility south of the National Mall without allowing a phone call. They also did not say more about why he had been arrested, he added. The White House and Park Police did not respond to requests for comment.
Late Friday, Mr. Trump claimed on social media that the “inside surface that was just installed” had been damaged by vandals.
Mr. Hearn said that he had “reached into the water to feel the characteristics” of a dislodged paint piece “still attached to the bottom.” He compared his actions to those of Jonathan Karl, an ABC News reporter who lifted a detached piece of paint at the pool on Thursday in a video the news organization published.
“I didn’t remove anything,” Mr. Hearn said. “I was bending and feeling this two-millimeter-thick, rubbery flap.”
Until his retirement 18 months ago, Mr. Hearn ran a company selling special materials for building canoes. That, he said, made him particularly interested in the materials contractors had used before the paint at the base of the pool began peeling.
Mr. Hearn said that he had already received offers of pro bono representation following his arrest.
“I’m getting a lot of support from my community,” he added.

