On Tuesday morning, a popular downtown building reflected an unfortunate situation–it had been vandalized with graffiti.

The Pioneer building was one of Tucson’s first high rise buildings, designed by local architect Roy Place in the early 1900s, and since then it has served as a landmark for the Tucson community. Now, the office and apartment building has been targeted by vandals with spray paint.

The Tucson Police Department is investigating the incident, which they believe happened on Monday afternoon.

The graffiti comes as a shock to many Tucsonans, as the building is a rich historic, heritage landmark.

The Pioneer building is not the first historic site hit by graffiti in recent years. The Rialto Theatre was tagged in July 2016, and the suspect was arrested less than a month after the incident. In April 2015, the Fox Theatre was hit by graffiti, with an arrest coming the following February.

Graffiti has been a concern for the community, especially as Tucson pursues it’s plan of downtown revitalization.

No arrests have been made. Anyone with relevant information is encouraged to report it anonymously to 88-CRIME.