The affected area of the Vietnam Veterans Memorial when the marking was discovered (above) and after it was cleared (below). (Photo via NPS)

The United States Park Police is investigating the appearance of red, waxy material on the Vietnam Veterans Memorial as an act of vandalism.

The National Park Service says the marking was discovered around 7:45 p.m. on Wednesday evening, and has been successfully removed by the National Mall and Memorial Park’s architectural conservator with water and a mild detergent.

The marking, which NPS says is likely red crayon or lipstick, covered only one of the more than 58,000 names of servicemembers killed or missing in action in the Vietnam War that are featured on the wall. Julio Victor Morales, a Marine from Philadelphia, was just shy of his 20th birthday when he was killed in Quang Tin province in May of 1967, according to the Vietnam Veterans Memorial Fund.

While the Park Police are investigating the incident as vandalism, they do not believe it is linked with other recent instances of graffiti, like earlier this week, when authorities found an explicit message in spray paint on the Lincoln Memorial and an undecipherable one on a Smithsonian sign in the 1400 block of Constitution Avenue.

Park Police request anyone with information about the incident to call 202-610-7515.

Updated with more information about Julio V Morales.